CONCHOLOGICAL WRITINGS. 93 



1. Siphalomphix, Raf. N. G. shell conical, opening oval acute, 

 end rounded, columella twisted with a tubular ombilic. It differs 

 from Agathina by the columella and ombilic. 



S. bonariensis Raf. or Ag. bonariensis, Raf. Six spires tip 

 nearly obtuse, first spire with a transversal angle — shell about one 

 inch long, whitish semi-transparent, brittle. 



2. Stegomphix, Raf. N. G. shell oval opening nearly round lips 

 not quite joined, the internal covering a small spiral ombilic. — There- 

 fore different from Cyclostoma and Paludina. 



St. elegans, Raf. {or Gyclostovia) oval with 5 spires, white, end 

 nearly obtuse yellow, spires with many small prominent transversal 

 strias. — One inch long or less very pretty. 



3. Biplicaria. Shell oval, opening pval, columella broadly 

 plaited with 2 folds or thick oblique ribs. — Near Voluta and Torti- 

 cella, but not marine. 



D. bonariensis, Raf. Oval obtuse smooth olive color with 2 

 spires only — small shell of half inch. 

 On five New Fresh Water Shells, of Bengal and Assam in 



Asia. 



They have been collected by Dr. Burroughs and are in my 

 cabinet. 



1. Planorbis albescens, Raf. nearly smooth whitish flattened on 

 the right side with 3 raised spires, only 2 on the left in a hollove, 

 opening hardly oblique. Size above half an inch. 



2. Paludina v'ltula, Raf. oval conical acute, 5 spires, swelled 

 before, olivaceous with narrow spiral brown bands. — Size about one 

 inch long. 



3. Paludina fragilis, Raf. oval swelled acute, 5 spires, smooth 

 [166] 



brittle, of a uniform dark or pale horny color. — Smaller than the 



last. 



4. Melania tessula, Raf. oblong, brown, seven spires, somewhat 

 tesselated by prominent ribs and small spiral strias, about one inch 

 long, I have 3 varieties. 1. first spire with duplicate strias — 2. do. 

 single strias, knobby tesselate shorter. 3. do. strias nearly obliterated. 

 Are they different Sp ? 



5. Melania costula, Raf. elongate, olivaceous brown, 7 or 8 

 spires, all with regular angular ribs lengthway, the first spire with 

 a spiral angle ending at end of opening. Over 1 inch, from the 

 river Gauges. 



