[2 collinge: on the anatomy of the genus myotesta. 



Taw crescentic, with ten broad ribs, slightly denticulating the basal 

 margin. 



Generative system crowded into the right anterior portion of the 

 body-cavity, excepting the hermaphrodite gland, which lies embedded 

 in the "liver," in the folds of the intestinal tract, dorso-posteriorly. 

 Well developed penis, passing into an epiphallus. Origin of retractor 

 muscle on the anterior portion of the right body-wall. Receptaculum 

 seminis with duct. 



Externally the members of this genus remind one somewhat of 

 those of Parmarion, Fischer, and Mariaella, Gray, but this is only a 

 superficial resemblance. 



A\'hen first examined the large shell-cavity seemed to have a 

 small irregular opening, but the examination of further and better 

 material leaves no doubt but that this opening was due to damage. The 

 rarify is completely closed, and contains at its anterior end, a flat, 

 non-spiral, plate-like shell; it is extremely thin, ovoid in outline, covered 

 by a thin periostracum, and composed of numerous minute, irregularly 

 shaped, calcareous particles. Immediately under this plate-like shell 

 lies the heart, and a little posterior to it, the kidney and ureter ; whilst 

 beneath the extreme posterior end of the shell-cavity, the rectum is 

 seen crossing from left toright. The lung is very small, and its exact 

 extent difficult to trace. 



Externally one notices that the visceral hump lies in a triangular 

 depression of the dorsum, so that the keel of the dorsum seems to 

 divide anteriorly in a Y-shaped m.anner. On the right side of the body 

 a deep groove passes from the respiratory orifice to the generative 

 orifice (PI. i, fig. 7, gr.). 



Myotesta fruhstorferi, Clige. 



PI. I, figs. 1 — 4. 



Myofe^a fDilisforferi, Cllge. : Journ. of Malac, 1901, vol. vii, 

 p. 118. 



Animal yellowish-brown, with brown mcjttling ; head and tentacles 

 light-blue ; mantle yellowish-brown with faint, net-like, brown markings. 

 Caudal mucous pore small. Peripodial groove very distinct. Foot- 

 fringe deep yellow with a few brownish splashes ; lineoles brown, 

 broad and irregular, with finer lighter coloured lines intervening. 

 Foot-sole dirty yellow. 



Length (in alcohol) 39 millim., breadth of foot-sole 3 millim. 



The (U-nerafire Oryavs (PI. i, fig. 4). — The vagina is a thick walled 

 tube, slightly bent and twisted, at its distal end a small receptaculum 



