21. Note on the taxonomic position of the Genus Campto- 
ceras. Benson and of Lithotis japonica, Preston 
(Mollusca Pulmonata). 
By N. ANNANDALE, D.Sc., F.A.S.B., Director, Zoological Survey 
of India ; and B. Prasuap, D.Sc., Superintendent of Fish- 
ertes, Bengal. 
[With Plate XII.] 
i 
Camptoceras, Benson. 
The genus Camptoceras was described in 1843 by Benson,! 
who in 1855? gave a more detailed description of C. terebra, 
the only species known to him. In 1871 Blanford § described 
as he said, to the sub-family Lymnacinae of the family 
Helicidae) and placed it between Ancylus and Limnaea, while 
Nevill® was of the opinion that it was allied to Succinea ; 
Chenu? and Fischer ® thought it to be allied to Physa, while 
Gude,’ agreeing with Nevill, places it in the family Succineidae. 
: e shell-characters are so remarkable that they provide 
little guidance as to the systematic position of the genus.’° 
Hist. iii, p. 465 (1843). 
: . Mag. Nat. Hist. Ser, 2, xv, p. 10 (1855). 
> Journ. As. Soc. Bengal xl, p. 40. pl. 2 (1871). 
+ Ann. Mag. Nat. Hist. Ser. 8, xvii, p. 160 (1916). 
: Mem. As. Soc. Bengal, vi, p. 56 (1916). 
Hand-List Mollusca i, p. 215 (1878). 
i, p 481, fig. 3554 (1859). 
* Faun. Brit. Ind. M i Me ie to (1914) 
nm. Bret, = llusca, ii, p. E 
° Godwin-Austen has pe A the same genus (Quart. Journ. 
rtain fossils from 
4+ i dia Bees Gade (loc 
cene of England and Henry Woodward agrees with him. ge Aor 
