SPURIOUS SPECIES OF PLANORBIS. 135 



PlanorbiH arcticiIS, Beck. — Shell dextral, horn-colored, thin, 

 convex and excavated in the centre above, concave below ; three and a 

 half cylindrical whirls. Diam. 2, 2'". (Mailer, I. c.) 



Planorbis arcticus, Beck in Moller, Ind. Moll. Gron. 5. — Morcu, Moll. 

 Gron. 76. 



I have not been able to obtain any authentic specimen for 

 figuring. The only published description is copied above. 



Spurious Species of Planorbis. 



Planorbis armigerus and P. wheatleyi are Segmentine. 



Planorbis parallelus, Say, J. A. N. S. II, 1G4 : Binney's ed. p. 63, is Helix 

 lineata (q. v.). Authentic specimens among Ferussac's shells in 

 the Garden of Plants are so labelled, as Dr. Gould informs me. 



Planorbis niger. I know nothing of this species mentioned as new, with 

 no description, by DeKay in New York Zoological Report of Dec. 

 20, 1839, p. 32. 



Planorbis complanatus, from Western Lakes, is mentioned by name only 

 by Ravexel, Cat. of Shells, p. 11. A foreign species has been de- 

 scribed under this name. 



Planorbis obtusa, Lea, is mentioned by Wheatley, Cat. of U. S. Shells 

 2d ed., p. 22, without description, giving Ohio as habitat. The name 

 is pre-occupied also. 



Planorbis eburneus, Chemn., is quoted doubtfully as synonym of PI. bi- 

 carinatus in Beck's Index, p. 118, ^ is 



Planorbis subcarinatus, Say (p. 119), of North America, without descrip- 

 tion, Phi/sa anceps of Menke being doubtfully cited as synonym 

 (Lister, Hist, cxxxix, 44): Delaware River; and subdistortus as 

 another variety. 



Planorbis fovealis, Beck (Ind. 119) : Delaware River. No description is 

 given, but reference to Lister, Hist, cxl, f. 47. 



Planorbis capillaris, Beck (Ind. 119) : Mexico; and Planorhis fuliginosus, 

 Beck (Ind. 120) : Mexico. No description. 



Planorbis evacuus. Villa = P. exacutus? 



Planorbis glans, DeKay= Glandina truncata. 



Planorbis alba? Sheppard (Trans. Lit. and Hist. Soc. Quebec, I, 195, 

 1829). — Shell umbilicated on both sides ; upper part of whirls flat, 

 lower convex ; aperture wide and angular. (Near Quebec.) = Plan, 

 albus, MiJLL. ? 



It is the Helix alba, Lix., but is not among Lamarck's species. 

 (Sheppard.) 



Planorbis spirorbts, Sheppard (Trans, of Lit. and Hist. Soc. Quebec, I, 

 195, 1829). — " One side flat, the other subumbilicate, reverse ; horn- 

 colored. (Near Quebec, at Etchemin.)" (Sheppard.) 



I do not know anything of this species, whether it is the P. spi- 

 rorbis of Europe or not. 

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