PLANORBIS DEFLECTUS. 25 



the question of priority; as the German peri- 

 odical, and Dr. Gould's work, were published the 

 same year. The later species might be called 

 diiatus, with the citation of the author to whom 

 it belongs as a species. 



PLANORBIS DEFLECTUS, Say. 



Plate 4. — Figs. 4 — 7. 



P. testa discoidea, ad periphseriam obtuse carinata, 

 utrinque concava et similiter excavata: labio in anfractuni 

 ultimum extenso: anfractibus 4 compressis. 



SYNONYMS AND REFERENCES. 



Planorbis DEFLECTUS, Say. Long's Expedition to St. 



Peter's river, p. 261, pi. 15, fig. 8. 

 Planorbis DEFLECTUS, Gould. Invert, of Mass., 136. 

 P. viRENS, Adams. Boat. Journ. N. H., v. 3, pi. 3, fig. 16. 



DESCRIPTION. 



Animal "dusky above, and with a still darker 

 line to tip of tentacula." — Gould. 



Shell discoidal, thin in texture, smooth, and 

 finely striate, with the margin obtusely cari- 

 nated: sides exhibiting about one-half of the 



K 4 



