Sphalloplana (Speophila) pricei Hyman 1937

Sphalloplana (Speophila) pricei (Hyman, 1937)

Speophila pricei Hyman, 1937:462.

Sphalloplana pricei.—Mitchell, 1968:615.

Sphalloplana (Speophila) pricei.—Carpenter, 1971:1284 [in part].

TYPE MATERIAL.—Holotype, one set of 6 slides of sagittal sections, USNM 20228. Paratypes, 5 specimens in alcohol, USNM 20236. Six specimens (one whole mount and 5 sets of serial sections mounted on 31 slides), designated as syntypes, AMNH 649 (see Feinberg, 1970:49).

EXTERNAL FEATURES (Figures 8, 24).—Mature specimens are up to 28 mm long and 3.5 mm wide, but maturity is observed also in smaller individuals. The color in life is a pure white apart from the intestinal contents, which may shine through the body wall. The anterior end has a straight or very slightly bulging frontal margin, with a median notch frequently seen when the animal is gliding. No auricular projections are developed, as the rounded lateral edges of the head do not extend anteriorly. Behind the head, the body first narrows, forming a necklike constriction, then widens again. In the greater part of the body, the lateral margins run parallel, converging again behind the region of the pharynx and meeting in the rather pointed tail end.

The anterior intestinal border shows a V-shaped indentation, the lateral branches extending somewhat anteriorly to both sides of the adhesive organ (Figure 19). The pharynx is inserted at about the middle of the body, its length amounting to approximately one-seventh the body length. The copulatory apparatus, visible in life as an elongated transparent field with a central opaque spot, is situated in the anterior half of the postpharyngeal section.

ANATOMY.—The structure of the adhesive organ (Figure 37), which in the retracted state forms a deep, folded invagination, is described well by Hyman (1937:464–465). No “snout-like” projection was visible, however, in specimens fixed with hot mercuric chloride solution. The modifications of the marginal epithelium with tall cells and large rhabdites are also analyzed by Hyman.

I have studied the reproductive organs of the species in eight sets of serial sections, including some of the type specimens. The ovaries are situated behind the third or fourth pair of lateral branches of the intestine. The numerous, rather small testes are not confined to the dorsal region, as Hyman indicates, but are located dorsally, ventrally, and in intermediate positions (Figure 44). The thin anterior vas deferens on either side runs along the ventral nerve cord, parallel to the oviduct and on the medial side of it. It expands at the pharyngeal level as the usual spermiductal vesicle. The copulatory apparatus appears rather much contracted in Hyman's Figure 11. In specimens killed in the extended state by a hot fixative, the apparatus is generally more elongated (Figure 57). The genital aperture (gp) leads into a common atrium (ac), which communicates widely with the anterior male atrium (am). The penis has a muscular bulb of moderate size and a large, very pliable papilla (pp), which is very variable in appearance, from conical to finger-shaped, often bent in various directions. The constriction at the middle of the papilla, mentioned by Hyman, is not a regular occurrence. The papilla is provided with a very feeble musculature, chiefly two thin layers of muscle fibers, one circular, the other longitudinal, below the external epithelium of the papilla. The two vasa deferentia (vd) enter the penis bulb ventrolaterally and proceed posterodorsally toward the midline. They open into the penis lumen either separately and close together or after first uniting to a short common vas deferens. The penial lumen is an elongated cavity, arching from the bulb toward the papilla and opening at the tip of the latter. The anterior part of the cavity has a glandular epithelial lining, the cells of which, staining deeply with eosin, project in some of the specimens into the lumen in a villus-like fashion. This anterior part is frequently widened and corresponds to a seminal vesicle (vs). Posteriorly, the cavity continues as a canal with somewhat variable diameter, the ejaculatory duct (de). Gland ducts with a homogeneous, faintly cyanophilic secretion enter the penis bulb from the surrounding parenchyma and open into the anterior portion of the ejaculatory duct. The common oviduct (odc) opens from the dorsal side into the atrium near the junction of the male and common atria. The bursa copulatrix (b) shows no peculiarities. Its outlet, the bursal duct (bd), starts as a straight, narrow canal but widens considerably in its posterior section, forming sinuous convolutions and acquiring a thicker muscle coat. This widened terminal part may be termed a vagina (v).

None of the epithelia of the copulatory complex are infranucleate.

DISTRIBUTION AND ECOLOGY.—Sphalloplana pricei inhabits several caves in Pennsylvania.

DAUPHIN COUNTY: Brownstone Cave: One specimen collected by John W. Price, 23 May 1936 (Hyman, 1937:466). LANCASTER COUNTY: Refton Cave (type-locality): several specimens collected by John W. Price, 20 January and 17 April 1936 (Hyman, 1937:466); several specimens collected by Jerry H. Carpenter, 20 May 1971; 10 specimens collected by Arnold Norden and Beth Ball, 4 February 1973. MIFFLIN COUNTY: Upper Johnson Cave: specimens collected by Charles E. Mohr and Kenneth Dearolf, 23 January and 27 February 1937 (Hyman, 1937:471; Dearolf, 1941:170).

TAXONOMIC POSITION.—The distinguishing characters of S. pricei are the following: Adhesive organ deeply invaginated, anterior intestinal border V. shaped, testes dorsal and ventral, penial papilla large with ejaculatory duct opening at tip, and entry of the vasa deferentia into the penis bulb ventrolateral. Carpenter (1970:85) considers S. pricei to include three more of Hyman's species of Speophila, S. buchanani, S. hubrichti, and S. hoffmasteri, which he lists as synonyms of S. pricei. An analysis of the morphological characters of these forms, however, justifies their standing as good separate species. Sphalloplana buchanani appears to have only dorsal testes (Hyman, 1937:469), but will need a more detailed reexamination; S. hubrichti differs from our species by having dorsal testes and not showing the V-shaped recess in the anterior border of the digestive system; S. hoffmasteri, by the arrangement of the muscles in the interior pharyngeal muscle zone, is to be removed from the genus Sphalloplana and placed into Macrocotyla (Kenk, 1975:333).