244 



NILS HJ. ODHNER 



Fig. 18. Nepionic shells of Tornatellinidae. a — //, X 50; /, X 25. «, Tornatellma bilamellaia 

 (typical form), palatal fold feeble; b, the same, a smaller shell (2 whorls); c, the same, a narrow 

 variety with less pronounced angularity of the last whorl; in a brood of 6 3'oung ones this was 

 somewhat narrower and less angled than the remaining shells; </, the same, a three-toothed 

 variety, young shell with 2 palatal folds, columella with an inferior callus, no angularity of the 

 whorls; e, T. conica (note the long parietal fold); f, T. callosa, a single nepionic shell, with 2 

 whorls, from the toothed ephebic stage; g, T. plicosa, a nepionic shell, with 2 V2 wliorls, from 

 the toothless ephebic stage; h, Fernandezia cylindrella, a nepionic shell with 2 '/^ whorls; 

 /, F. buHmoides, a nepionic shell with 2 whorls. 



theca with a very long stalk; the bladder is situated upon the prostata gland. 

 There are no other accessory formations attached to the female portion. 



The vas deferens follows the stalk of the spermatheca down to closely 

 inside the genital orifice. Its course is entirely straight, till it debouches in the 

 vestigial penis which is represented by a mere papilla as in Tornatellina. 



