1918.] ToKTO Kabtjraki : Triclads of the InU Lahe. 193 



manifestly stands in favour of the view (Schultze,i Woodworth,^ 

 BergendaP and Weiss*) that the formation of the spermatophore takes 

 place in the penis-lumen, and not in the receptaculum seminis. Still 

 another point which lends probability to this view is the fact that in 

 the present species the spermatophore is tubular in conformity with 

 the general shape of the lumen of the penis. 



The receptaculum seminis gives rise posteriorly to the vaginal canal, 

 which runs above and somewhat to the left of the penis. It opens into 

 the penis-sheath from above. The cylindrical epithelium of its wall 

 rests on a delicate basement membrane, beneath which is a muscular 

 coat consisting of an internal circular and a thinner external longitudinal 

 layer. Further, the vagina is surrounded by a large number of pyriform 

 cells, which appear to represent the unicellular glands seen in the 

 preceding form in the same situation. 



Planaria bilitieata, n. sp. 

 PI. XXVII, fig. 3. 



This new species is represented again by a single specimen (W. -^-j^), 

 taken on the lower surface of a stone in a small stream in Yawnghwe 

 State above Fort Stedman, at an altitude of about 3,500 ft. above 

 sea-level. Southern Shan States. 



Externally the specimen looks very much like PI. gonocephala, 

 subtentaculata, maculata, ahorensis, etc., so far as concerns the shape 

 in the preserved condition. The head is somewhat markedly triangular, 

 with a slight prominent lappet on either side. There thus exists behind 

 the head a somewhat neck-like constriction. The trunk in the hind 

 parts gradually tapers to the bluntly pointed posterior extremity, which 

 in the present specimen bears a sign of regeneration in that it exhibits 

 pigmentation in a somewhat less degree than the rest of the body-surface 

 (fig. 3). The worm measures 8 mm. long by 2-5 mm. across in the 

 broadest part of the body. 



The colour of the dorsal surface is darkish olive-brown, with two 

 longitudinal well-defined blackish bands running on either side of the 

 median line from the eyes to the posterior end. These bands are 

 narrower and much more distinctly defined than those sometimes 

 observed in PI. gonocephala. The ventral surface is as usual of a some- 

 what lighter colour than the dorsal. 



The crescentic eyes, each situated at the inner edge of an oval 

 colourless area, are situated about midway between the anterior extrem- 

 ity and the line connecting the apices of the lateral head lappets, and 

 are separated from each other by a space about equal to the shortest 



1 Schultzv, M., 1854. " Zoologische Skizzen." Zeilsckr. f. iviss. Zool., Bd. l\, pp; 

 186, 187. 



2 Woodworth, W. McM., 1891. " Contributions to the Morphology of the Tiirbel- 

 laria I. On the structure of Phagocata gracilis Lcidv." Bull. Mus. Com]}. Zool. 

 Harvard Coll., Vol. XXI, pp. 31, 32. 



' Bergendal, D., 1892. " Einiges iiber den Uterus dcr Tricladen." Feslschr. z. 70 

 ten Gehurtstag R. Leuckarts, p. 318. 



* Weiss, A., 1910. " Beitrage zur Kcnntnis der australischen Turl)ellarien. J, 

 Tricladen." Zeilschr. f. wiss. Zool, Bd. XCIV, pp. r)S4-r)80, 



