PLANORBIS. 



107 



species. The whirls are more rapidly enlarging, more swollen, and the lip 

 more shouldered. An unusually large specimen measures long. .G3, lat. 

 .58, alt. .27. 



Ilab. Mazatlan ; not uncommon. Liverpool collection. (^Carpenter.) 



Planorhis tumens, Carpenter, Brit. Mus. Mazatlan Cat. 181. 

 Planorhis ajffinis, Carpenter iu Caff. Prov. (not Adams). 

 Planorhis taint (jlophilus, Menke, Zeit. f. Mai. 1850, p. 1G3 (not D'Orbigny, 

 teste Carpenter). 



Fig. 180 is drawn from ti specimen received from Mr. Carpen- 

 ter. The original description is given above. 



Cat. No.lNo. ofSp. 



912.) 

 9121 

 9146 



Sail Francis 

 Petaluma. 



Prom ■whom received. 



Judi/e Cooper. 

 Dr. Gould. 



Type. 



Figured. Authentic. 



Fig. 181. 



C=D 



Plaisoi'luis Iiavaiiensis, Pfeiffer. — Shell discoid, thin, pale 

 horn-colored or yellow, very delicately and densely striate ; above and 

 below planulate, and having an umbilicus in the centre ; whirls five, sub- 

 rotund, moderately increasing, separated by a deep suture ; 

 aperture oblique, roundly lunate. 



Shell discoid, thin, fragile, pale horn or yellowish in color, 

 with very delicate and numerous striae ; both above and 

 below flattened and umbilicate in the centime, but somewhat 

 more deeply so above ; whirls five, regularly increasing, 

 rounded, separated by a tolerably deep suture ; ajDerture 

 oblique, round, somewhat lunate. Diam. (greatest of largest 

 specimen) about 4 lines, height \^. 



Received from Herr Dr. L. Pfeitfer, who found it in swamps 

 near Havana. Also from Dr. F. Roemer, who found it iu 

 Texas. 



It has many analogies with PL peregrinus, D'Orb., of Chile. (KUster.) 



Planorhis havanensis, Pfeiffer in Wiegm. Arch. f. Nat. 1839, I, p. 354. 



— KiisTER in Chemnitz, ed. 2, p. 58. pi. x, f. 32-34. 

 Planorhis terverianus, D'Orbigny, Voy. Cub. 194, tab. xili, f. 20-23. 



I have seen no specimen of this species ; the above extracts 

 and figures are from the second edition of Chemnitz. 

 The following is Pfeiffer's description : — 



Planorhis havanensis. — Shell discoidal below, above more concave, light 

 horn-color ; whirls .four, regularly increasing, terete ; aperture lunate. 

 Diam. 5, alt. 1^'". {Pfeiffer.) 



