THE TANGANYIKA PROBLEM. 



247 



spermatic groove (Fig. 29) running from the opening of 

 the genital duct along the body and on to the foot below 



Fig. 29. — Semi diagram of the anatomy of Tangcuiyicia rufofilosa. 

 The mantle opened from above, and the nerves in black ; 

 ay st. s., crystalline style.; St., stomach ; b. p., brood pouch. 



the tentacles on the right side, just as it does in Strombus, 

 Pteroceras, or Littorina. In the female Tanganyicia this 

 genital groove is also present, and leads from the genital 



