dcsimg

Comprehensive Description

provided by Memoirs of the American Entomological Society
Narceus annularis (Rafinesque)
Figures 1, 7, 10, 16, 20, 22-29, 35-43, 64-68, 82-83, 86-88, 192-193
Rhexenor annularis Rafinesque, Annals of Nature, p. 8. 1920.
Jiilus marginatus Say [not Olivier, 1792], Journ. Acad. Nat. Sci. Philadelphia,
vol. 2, p. 105. 1821. New synonymy. Spirobolus marginatus, Newport, Ann. Mag. Nat. Hist., ser. 1, vol. 13, p. 269.
1844. Sporobolus marginatus, Wood, Trans. Amer. Philos. Soc, vol. 13, p. 207, fig. 38
[not 35]. 1865. lulus americanus. Wood, ibid., p. 207. lulus incertus, Wood, ibid., p. 207. lulus ornatus. Wood, ibid., pp. 207, 208. lulus atratus. Wood, ibid., pp. 207, 208. Spirobolus agilis Cope,. Proc. Amer. Philos. Soc, vol. 11, p. 181. 1869. New
synonymy. Spirostreptus ignobilis Humbert and Saussure, Rev. Mag. Zool., ser. 2, vol. 22,
p. 177. 1870. New synonymy. Spirobolus ignobilis, Bollman, Ann. New York Acad. Sci., vol. 4, p. 43. 1887. Spirobolus marginatus, Bollman (in part), Proc. U. S. Nat. Mus., vol. 11, p. 343.
1888. Arctobolus onondaga Cook, Harriman Alaska Exped., vol. 8, p. 64. 1904. Spirobolus 'marginatus, Brolemann, Ann. Soc. Ent. France, vol. 83, p. 2, fig. 2.
1914. Spirobolus marginatus, Williams and Hefner (in part), Ohio State Univ. Bull.,
vol. 33, p. 123. 1928. Spirobolus spinigerus, Williams and Hefner, ibid., p. 123. Arctobolus marginatus, Loomis, Journ. Washington Acad. Sci., vol. 23, pp. 100-
109, fig. 1. 1933. Arctobolus marginatus, Loomis, Bull. Mus. Comp. Zool., vol. 92, p. 397, fig. 12.
1943. Spirobolus orophilus Chamberlin, Bull. Univ. Utah, biol. ser., vol. 8, no. 2, p. 8,
figs. 17-21. 1943. New synonymy. Spiroholns scotti Chamberlin, Proc. Biol. Soc. Washington, vol. 56, p. 148, figs.
12-14. 1943. New synonymy. Spirobolus orophilus Chamberlin, Proc. Acad. Nat. Sci. Philadelphia, vol. 99, p.
46. 1947. Spirobolus marginatus, Chamberlin, ibid., p. 46.
Spirobolus americanus, Hoffman (in part), Florida Ent., vol. 34, pp. 15-16. 1951. Arctobolus marginatus, Snodgrass, Arthropod Anatomy, pp. 242-246, figs. 63C, Rhexenor annularis, Hoffman and Crabill, Florida Ent., vol. 36, pp. 81, 82. 1953. Arctobolus onandaga [sic], Hoffman and Crabill, ibid., pp. 81, 82. Narceus annularis, Hoffman and Crabill, ibid., pp. 81, 82. Narceus americanus, Chamberlin (in part), Amer. Midi. Nat., vol. 50, p. 150.
1953. Narceus annularis, Chamberlin, ibid., p. 151. Narceus orophilus Chamberlin, ibid., p. 151. Narceus marginatus, Causey, Journ. Kansas Ent. Soc, vol. 28, pp. 71, 72, figs.
la, 3. 1955. Narceus annularis. Causey, ibid., p. 74. Arctobolus onondaga. Causey, ibid., p. 74. Narceus scotti, Causey, ibid., p. 75. Narceus annularis, Chamberlin and Hoffman, U. S. Nat. Mus. Bull., no. 212, p.
166. 1958. Narceus orophilus, Chamberlin and Hoffman, ibid., p. 167. Narceus scotti, Chamberlin and Hoffman, ibid., p. 167. Spirostreptus ignobilis, Chamberlin and Hoffman, ibid., p. 168.
Nomenclatorial Considerations. — Since its reintroduction into the literature in 1953, the name annularis has been appHed to specimens from New York, with the single exception of a record published by ChamberHn ( 1953) for Illinois. It has been supposed that Rafinesque's description referred to the same population described by Cook as onondaga. I have examined Cook's type and find it to be a specimen of the species that is common from Canada south to Virginia and western North Carolina, and west through the north central states. I have examined many specimens from New York and can find no other species there. It is thus apparent that anmdaris is the oldest name for the northern species of Narceus.
Say's name Jidus marginatus is a junior primary homonym of Jidus marginatus Olivier, as pointed out by both Bollman and Hoffman. (Many early writers regarded Olivier's Iidus marginatus, 1792, as a reference to the earlier Oniscus marginatus of de Villers, 1789.
Careful examination of Olivier's work reveals that this is not the case. In every instance where Olivier mentions a species described by someone else, he gives a synonymy listing all previous nomenclatorial combinatons. No such synonymy is given for lulus marginatus and it must be regarded as a name proposed for a new species by Olivier, not as a reference to de Villers' species. Thus, regardless of whether or not marginatus Olivier and marginatus de Villers are zoologically synonymous in Glomeris, Julus marginatus Say is a primary, not secondary, homonym of lulus marginatus Olivier). It is thus of only academic interest to determine which spirobolid species Say actually described. An examination of the original description of marginatus immediately shows why there has been no agreement between later workers as to the species it designates. It is my opinion that Say considered all the spirobolids in eastern North America to belong to one species and intended his description to apply to all of them. For example, the color described in Say's first paragraph is typical of Narceus while that in the last paragraph, " It varies in color; the margin of the segments and all beneath are sometimes white ", obviously refers to Chicobolus. Inasmuch as the characters of Chicobolus are given as exceptions, it seems safe to assume that Narceus species were the ones upon which the main part of the description was based. An attempt logically to determine whether Say was most concerned with the northern or the southern species of Narceus would be useless, particularly in view of the fact that, in addition to being a homonym, marginatus would be a junior synonym in either case. An arbitrary assignment seems fully warranted; I therefore accept Causey's (1955a) designation of Philadelphia as the type locality. Only the northern species of Narceus occurs there and, hence, marginatus is here listed as a synonym of annularis.
No attempt has been made to list all of the hundreds of references to marginatus that appear in the literature ; in most cases it is impossible to tell which species was actually involved. Only those references are mentioned that made significant contributions to the history of the name or to the knowledge of the animal. '' Spiroholus marginatus " will doubtless continue to be " the " milliped in textbooks and supply house catalogues. The publishers of such works are welcome to the name.
Spirobolus agilis Cope is based on an immature specimen ; the type is lost. I have collected at the type locality and have seen many specimens from there. Both annularis and americanus are found in the area but the former is far the more abundant. I, therefore, list agilis as a synonym of annularis.
The type of ignohilis is supposed to be in the Vienna Museum but a personal communication from Dr. Friedrich Kasy of that institution reveals that it cannot be found. I believe, however, that the original description gives enough information for an identification to be made. The statement, " primo segmento utrinque tigonali-rotundato, secundo in processum subacutum marginis antici infere producto," seems sufficiept tp consider this a spirobolid. The segment count of 55, length of 68 mm., width of 5.5 mm., and easily calculated L/W value of 12.36 all combine to make it almost certain that ignohilis is a synonym of annularis, as reference to the tables for the various genera will show. BoUman (1887) apparently guessed that this might be the case inasmuch as he gave the range for this species as " Eastern Province, northern part."
I have not seen the type of orophilus but I have seen a specimen reported by Chamberlin (1947) as that species. It is typical of annularis. The drawings with the original description appear to be of annularis. The segment counts (51—57) given by Chamberlin indicate that he had both annularis and americanus before him (both occur at the type locality). Judging from the drawings (americanus specimens from that locality have much longer and narrower lobes of the fourth and fifth coxae) and from the width of 6 mm., I think it probable that the type is a specimen of annularis.
I have seen the type and a male paratype of scotti; they are normal specimens of annularis. Both other new species (Spirostrephon lactarium and Sigmoria houstoni) described by Chamberlin from Houston in the same paper with the de^'crifition of scotti are, like scotti, typical Appalachian forms and are otherwise unknown in Texas or neighboring states. I feel, therefore, that it is highly probable that these three species, all collected by R. Scott, were not taken in Texas, and that they were either accidentally mislabelled or were collected in some other " Houston " such as Houston County, Tennessee.
Diagnosis. — Distinguished from gordanus by the shape of the collum, the shallower antennal groove, the absence of a carina across the parietal sclerite, more segments and fewer facial setae, longer legs, more produced male pregenital coxae, and characters of the genitalia of both sexes. Differs from americanus in the characters given in the key and discussed in the remarks below.
Description. — L of males 46-101 mm. (71.1), of females 46-109 mm. (72.2) ; W of males 4.5-8.0 mm. (5.96), of females 4.3-9.2 mm. (6.46) ; L/W of males 9.2-15.0 (11.9), of females 8.4-14.9 (11.2). Segments 51-59 (55.1). Generally dark brown with reddish hindbelts and leg's ; the red disappears in alcohol.
Face broad ; lateral corners of clypeus distinct. Antennal groove moderately deep, well-delimited both anteriorly and posteriorly. Surface of parietal sclerite sinuate but without a carina ; sclerite tapering caudad. Mandibular cheek moderately grooved. Eyes per patch 32-57 (42.5). Clypeal setae 4 (atypical specimens, usually with all or most setae on one side) -12 (8.1) ; labral setae 7-18 (13.0).
Collum usually covering only vertex of head, leaving eye patches, antennal grooves, and mandibular cheeks exposed; anterior margin of collum usually angling slightly caudad at level of eye patches, and shallowly emarginate below the angles. Second segment much produced below ends of collum, the production often long, narrow, and relatively acute ; a strong ridge along anterior margin of production, this much stronger than striae on median surface of production.
Tergites densely punctate and with numerous small regulae.
Coxae of male 3rd legs produced ventrad, lobe thus formed not much expanded laterally (figures 35-38), its lateral margin often running obliquely mesoventrad; no deep groove across cephalic surface although shallow depression sometimes evident. Coxae of male legs 4 and 5 produced, the lobes subtriangular, broad, seldom turgid, usually bent slightly cephalad and crossed by several folds ; lobes of these pairs of legs subequal. Lobes of 6th legs similar but shorter. Coxae of 7th legs sometimes produced, sometimes not, the production always short. Third segments of male legs 3-7 much longer than 2nd segments, compressed, usually concave on caudal surface. Coxae of female 3rd legs not produced. Legs relatively long, exceeding sides of body when held horizontally.
Shape and length of mesal process of sternum of anterior gonopods variable, usually relatively broad. Coxal endites narrower than in Spirobolus, their mesoventral corners very broadly rounded ; ventral margins usually strongly sinuate, degree of such curvature variable. Prefemoral endites of posterior gonopods long, relatively narrow, distally rounded.
Cyphopod thicker distally than in americanus, distal lobe usually curved slightly caudad thus causing shallow transverse depression on caudal surface. Lateral flange not toothed, its distal corner sometimes sharp but not greatly produced.
license
cc-by-nc-sa-3.0
bibliographic citation
Keeton, W.T. 1960. A Taxonomic Study of the Milliped Family Spirobolidae (Diplopoda: Spirobolida). Memoirs of the American Entomological Society vol. 17. Philadelphia, USA