94 PLEKOCHEILUS-EURYTUS. 



Helix onca ORB., Mag. de Zool., 1835, p. 8 ; Voy. dans FAmer. 

 Merid., pi. 30, f. 1, 2. B. onca ORB., t. c., p. 295. REEVE, Conch. 

 Syst., ii, pi. 173, f. 3 ; Conch. Icon., pi. 18, f. 108. PFR., Monogr., 

 ii, p. 17. Bulinus onca SOWB., Conch. Illustr., f. 80. Placostylus 

 onca BECK, Index, p. 58. Bulimus onza ALB., DieHel., (2) p. 195. 



Not deeply striate as B. floccosus is, but resembling that species 

 in form. 



P. LYNCICULUS Deville & Hupe. PL 36, figs. 82, 83. 



Shell imperforate, ovate-oblong, thin, subpellucid, but little shin- 

 ing, obsoletely subdecussated. Whitish-rose, irregularly marked 

 with longitudinal dots and lines of chestnut, covered with a thin 

 tawny cuticle. Spire conoid, the apex somewhat obtuse, roseate ; 

 suture simple. Whorls 5, slightly convex, rather rapidly increas- 

 ing, the last somewhat ventricose, subdeflexed in front. Columella 

 roseate, oblique, narrow, and twisted, its spiral turns visible inside 

 to the apex from the base. Aperture oval, acuminate above, within 

 colored like the outside, rose-tinted, three-fifths the shell's length ; 

 peristome simple, rose-tinted, slightly expanso-reflexed, the mar- 

 gins joined by a very thin callus; right margin regularly arcu- 

 ate, columellar margin a little dilated, adnate. Alt. 50, diam. 25 

 mill. (Hidalgo). 



Mission of Sarayacu, on the river Ucayali, Peru (Castelnau) ; 

 Napo, Ecuador (Martinez). 



B. lynciculus DEVILLE & HUPE, Revue Zoologique, 1850, p. 640, 

 pi. 15, f. 1. HUPE, Anirn. nouv. ou rares rec. pendant 1'Exped. 

 dans les parties centr. de FAmer. du Sud., sous la direction du 

 Comte F. de Castelnau, Moll., p. 40, pi. 5, f. 3, 3a. HIDALGO, Mol. 

 Viaje al Pacif, p. 94. PFR., Monogr., iii, p. 381 ; iv, p. 449 ; vi, p. 

 88 ; viii, p. 34. 



Compared by Hupe with B. onca, a longer, thinner shell, and B. 

 taylorianus, from which the simple suture and coloring separate it. 

 Hidalgo says that the longitudinal lines are more irregular in lynci- 

 culus, some long, some short, and others interrupted, formed of 

 chestnut dots, which, over the rest of the surface, are sparsely scat- 

 tered. . 

 P. SEMPERI Dohrn. PI. 37, figs. 92, 93, 94. 



Shell rimate, acuminate-oblong, obliquely regularly plicate-striate, 

 thin, semi-pellucid ; reddish-corneous, sparsely dotted and flamed 

 with brown. Spire somewhat acute, conic. Whorls 5J, slightly 



