NEW SPECIES OF FLATWORMS HYMAN 427 



M-hite strip of sensory nature forming the body edge. The Sinnes- 

 kante has been fully treated by von Graff in his classical monogi-aph 

 on the Terricola (1899). Cross section of the body crescentic, gently 

 convex above, plane or sliglitly concave below, entire ventral surface 

 modified to a creeping sole, as in other members of the genus. Mouth 

 about three-fourths the body length from the anterior end; genital 

 pore of type specimen 7 mm posterior to the mouth. Postpharyngeal 

 portion of the body of both type and paratype removed and cut into 

 serial sagittal sections. 



Color. — Dorsal surface with a broad middorsal light -yellow stripe, 

 rest of dorsal surface with a mottled dark-brown pattern on the 

 same light-yellow background (fig. 48, d). Details of the pattern in 

 a lateral half are shown in figure 49, «; there is simply an irregular 

 marbling with dark brown and light yellow. In the paratype there 

 appears to be more yellow and less dark brown in the marbled pattern 

 with larger yellow areas near the margin ; but it is probable that the 

 color has faded during the long sojourn in alcohol. Ventral surface 

 dull white, with a little brown pigment on the head. 



Reproductive system. — Both specimens have a mature copulatory 

 apparatus, but the accompanying gland cells are much better de- 

 veloped in the paratype. Sagittal section combined from type and 

 paratype shown in figure 49, b. The genital pore leads dorsally 

 into the large genital atrium, divisible into an anterior extension, 

 the male atrium, containing the penis papilla, and a posterior exten- 

 sion, the female atrium. Penis with poorly developed bulb; penis 

 Ijapilla large, of elongated conical form, extremely muscular, the 

 interior filled with sinuous muscle fibers, which course mostly in a 

 longitudinal direction and at the penis base curve posteriorly to be- 

 come continuous with the muscle layer of the genital atrium and 

 the parenchymal fibers. The penis papilla is clothed with a low 

 cuboidal epithelium in which cell walls could not be distinguished 

 (fig. 49, c) ; beneath the epithelium there appears to be no definite 

 muscle layer except toward the penis base but a syncytial network. 

 This is crossed at intervals by bundles of muscle fibers, which reach 

 the surface of the penis, sometimes elevating this into a small papilla. 

 Where these muscle bundles come to the surface, the regular epithe- 

 lium appears to be modified (fig. 49, c), but the available sections 

 are not thin enough to reveal the histology of the terminations of 

 these muscle bundles. They seem to inclose some large cells, which 

 may be gland cells. Fuhrmann (1914a) has observed similar muscle 

 bundles terminating in papillae in the penis of GeopJana vonguteni 

 from Colombia. He believes these papillae contain gland cells whose 

 contents are squeezed out by the muscle fibers encircling them. He 

 also found the muscle bundles indicated in Geoplana cameUm. Penis 



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