Sphalloplana (Sphalloplana) kansensis Hyman 1945

Sphalloplana (Sphalloplana) kansensis Hyman, 1945

Sphalloplana kansensis Hyman, 1945:478.

Sphalloplana (Sphalloplana) kansensis.—Carpenter, 1971:1284.

TYPE MATERIAL.—Holotype, set of serial sections on 3 slides, AMNH 311–313.

The species was described by Hyman (1945:478–479) from one preserved specimen. An examination of her slides showed that the worm was badly contorted and not suitable for a detailed anatomical analysis. Another specimen was sent to the writer by Russell M. Norton, unfortunately also in a badly preserved state, which made its exact study impossible. The following description must, therefore, be based on the data presented by Hyman.

EXTERNAL FEATURES.—No illustration of the living animal is available. It is a rather large (20 mm long), broad, and thin planarian, white and eyeless, with a truncate anterior end.

ANATOMY.—The adhesive organ is a depression equipped with eosinophilic glands and a moderate musculature. It is deeper than is generally seen in species of the subgenus Sphalloplana, but not as highly differentiated as in representatives of the subgenus Speophila, a feature which has been noticed also by Carpenter (1970:81). Hyman states that the rhabdites in the marginal zone are only little larger than elsewhere.

The testes are dorsal. The penis has a slightly developed bulb and a short, rounded papilla (Figure 48, pp). The vasa deferentia unite outside the bulb to form the ejaculatory duct (de) that first ascends dorsally, then bends posteriorly and opens at the tip of the papilla. The male atrium (am) is elongated and lined with a very tall epithelium, the common atrium very small and its wall bears irregular small blind epithelial outgrowths (da) that are very characteristic of the species. The bursal canal (bd) is very long and slender, the bursa (b) being separated from the penis bulb by a considerable distance, as is the case also in my specimen. The terminal portion of the bursal duct turns ventrally and is considerably widened. The long common oviduct (odc) enters the roof of the male atrium.

DISTRIBUTION.—Sphalloplana kansensis is known only from the type-locality, Purity Springs, a walled spring located about 4 miles east of Augusta, Butler County, Kansas. Hyman's specimen was collected there on 18 March 1942 by Leslie Hubricht, another specimen by Russell M. Norton on 12 June 1964. I visited this locality on 22 May and 13 July 1967 and again on 10 June 1970 without finding any planarians. Jerry Lewis was so kind as to expose in the spring traps baited with fresh shrimp in August 1973, also without results.

TAXONOMIC POSITION.—By its moderately developed adhesive organ S. kansensis is a species intermediate between the subgenera Sphalloplana and Speophila, as Carpenter (1970:81) pointed out. Many aspects of its morphology are unclear, and Hyman's slides show a great deal of distortion of the structures of the copulatory complex due to muscular contractions and possibly some artifacts. The epithelial outgrowths on the wall of the common atrium are reminiscent of the atrial diverticula of S. evaginata, but their shape appears to be quite different. A clearer picture will ensue only upon reexamination of properly preserved specimens.