RATXADVIJMA. 



/O 



Au amiitorial organ (dart- sac) present, large aud cylindrical ; 

 no calcareous dart' found, but a short blunt muscular papilla. 

 Spermatlieca sessile. The vas deferens passes into a kale-sac, 

 which is joined to the penis -sheath, some distance from the 







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[Fig. 38. — Uutiiudvij)ia irracliaiit'. 



i inimal from viglx side, showing the sliell- and dorsal lobes ; also part of, 

 from the left side. The shell-lobes are curled up in the si)U-it.-speeiiuen ; 

 the dotted line on visceral sac indicates their extension in life. X l^J. 



B. Part oF genitalia sliowing the typical male organ of Arhiphanta. x3-4. 



0. Jaw and leelli of the radula. x2G8.] 



retractor muscle, by an ei^iphallus : ciecum of penis straight, as in 

 Ariophanta. 



This genus differs from Jadrdia chiefly in the possession of 

 shell-lobes to the mantle, and in the absence of lateral cusps to 

 the teeth of the median bund in the radula. 



