224 MVTILU3, NAUTILUS. 



Sec. B. Convex or ventricose. Shell transverse / 

 hinge simple, destitute of teeth ; shell with three 

 obsolete muscular impressions. ANODOMTA of 

 Bruguieres. 



cataractus, (toothless muscle,) shell thin, fragile, 

 translucent, oblong-oval, convex ; covered with 

 a radiated olive-green epidermis ; pearly with- 

 in ; beaks nearly central ; front margin brown* 

 Length about two inches and a half, breadth 

 four and a half. 



jnarginatus, shell very thin, fragile, somewhat 

 compressed, translucent, subovate ; epidermis 

 olive-green, paler on the disk and greener be- 

 fore ; anterior margin fuscous ; beak nearer to 

 the posterior end ; bluish-white within, edges 

 whitish. 

 See MS. P. 



N. 

 53. NAIS. Spec. 10. 



firoboscidea, with single lateral bristles and very 



long proboscis. Three-fourths of an inch long* 



In clear water an inch long. 

 $erpentaria, body serpentine, with red spiral in- 



testines and triple black collar. In stagnant 



water. An inch long. 

 vermicularis, without lateral bristles ; chin beard- 



ed. In stagnant water. One-sixth of aa inch 



long. 

 See MS. P. 



9 4. NAUTILUS. Spec. 31. 



(nautilus,) aperture of the shell cor- 

 date, with obtuse and smooth whorls, Pearly 

 within. 

 Sec MS, P. 



