MOLLUSCS, VERMES AND HYDROZOA 



Found at Lower Cape Fear river in the vicinity of Wilmington, N. C. 

 No other locality has been reported. 



FIG. 171. Cape Fear river Snail, Planorbis magnificus. Four views. 



There are many other smaller species of Planorbes but their size 

 would preclude their use in the aquarium, though they are nearly all hardy 

 and will survive, except the very cold water species. 



Segmentina. These snails differ from the Planorbes in having pro- 

 jections or teeth within the aperture of the shell, which is discoidal with 

 but few of the whorls visible on both sides. 



S. armigerus. Fig. 172, has a light-brown polished shell 5^ to ^ inch 

 in diameter, with the lip much darker. The four sub-cylindrical whorls 

 are slightly keeled 

 upon the left side and 

 show faint lines of 

 growth. The right 

 side is nearly planed 



with a slightly de- ^'®- ^^^• Segmemina armigtrus. Enlarged. 



pressed centre. The body is a dull grey. It is a tiny insignificant snail 



to but little purpose in the aquarium. Quite generally met with in the 



Eastern and Middle States. 



S. wheatleyi. Fig 173, is a still smaller species, rarely over ^ inch in 



diameter, haying a slightly keeled shell with the two and a half whorls 



distinctly outlined on 

 the right side and lost 

 in the depression of 

 the left side. The 

 aperture is at an angle 

 FIG. 173. &^»«'/»««"5"'/<y/. Enlarged. pointing to the left. 



Inhabits rivers and lakes of the Eastern and Middle States. 



235 



