27 



PLANORBIS PARVUS, Say. 



PLATE 4. FIGS. 1923. 



P. testa simplice, minimi, tenui, laevi, valde compressa; 

 supra in medio impressa; infra late et minime excavata: 

 anfractibus 4, rotundatis, utrinque pariter conspicuis: suturis 

 impressis. 



SYNONYMS AND REFERENCES. 



P. PARVUS, SAY. Nich. Encyc., Am. ed., pi. 1, fig. 5. 



" " GOULD. Invert, of Mass., p. 209, fig. 139. 

 P. ELEVATUS, ADAMS. Boston Journ. N. H., 3, pi. 3, fig. 15. 



" " GOULD. Invert, of Mass., p. 207. 

 LISTER, tab. 139, figs. 4544? 

 "FAVANNE, pi. 63, fig. 3. DILLWYN." Say, MS. 



DESCRIPTION. 



ANIMAL brown, foot extending from the labrum 

 to the centre of the shell, rounded posteriorly, 

 sides parallel. 



SHELL small, compressed, minutely striate, 

 smooth, flat above, with the centre impressed: 

 left side with a broad, shallow concavity: whirls 

 four, a great part of them, with the apex, visible 

 to the centre, on both sides: sutures equally 



