202 



PUPILLIDAE AND RELATED GROUPS. 



similis (Brug.), -^. partioti (Moq.), A. secale (Drap.) and 

 Sandahlia cylindrica (Mich.), From the latter have been 

 taken figures of the genitalia (pi. 30, fig. 3) and radula (text- 

 fig. 11) of M. avenacea, of the jaw (pi. 31, fig. 2) of M. 

 similis, of the genitalia (pi. 31, fig. 1) and jaw (fig. 3) of 

 Ahida secale and of the genitalia (pi. 30, fig. 5) and carrefour 

 (fig. 6) of Sandahlia. 



OTTVm.,os 





n 



23 





1 a 



Fig. 11. Modicella avenacea, after Steenberg. 



In all these, the spermatheca (rs) is of the short type (im- 

 bedded in the uterus) but long-stalked (pd) ; the uterus (ov) 

 is highly convoluted; the prostate (pr) is about as long as 

 the uterus; the oviducal cul-de-sac is long and cylindrical; 

 the penis (pe) is simple (although with a free apical caecum 

 in some species) and receives the penial retractor (rp) near 

 its middle, which is often connected by fibers to the epiphallus 

 (ep) ; and the right free retractor sends branches to the base 

 of the penis as well as to the atrium. The unicuspid central 

 and inner laterals of the radula in Modicella distinguish it 

 markedly from the other two, which are mainly distinguished 

 by their shell-characters. 



