PLEKOCHEILUS-EURYTUS. 75 



The typical form of this species is rather thin and beautifully 

 variegated with dark spots (often coalescent into irregular streaks) 

 bordered on the left with light ; and in the aperture this pattern is 

 conspicuous. It is connected, however, by intermediate specimens 

 with the following : 



Var. LAMARCKIANUS Pfr. PI. 32, fig. 38. 



More solid and opaque, dark chestnut with few small scattered 

 darker spots, mostly oblique, and hardly showing within the dark 

 fleshy-brown aperture. Spire often superficially subplicate. 



Alt. 48 to 62 mill. 



Andes of U. S. of Colombia, 8,000ft. alt. (Funck) ; La Esperama 

 estate, near Rio Negro (Bland). 



B. lamarckianus PFR., P. Z. S., 1847, p. 229 ; Monogr., ii, p. 45. 

 REEVE, Conch Icon., pi. 24, f. 156. BLAND in C. B. Ad., Contrib. 

 to Conch., No. 12, p. 231. Mouss., Malak. Bl.,xvi, p. 173 (1869). 



Reeve's figure, which I have copied, represents a specimen 

 somewhat larger and more obese than those before me, from Cum- 

 ing and Bland. 



Var. AMPULLAROIDES Mousson. PL 32, figs. 39, 40. 



Larger than B. coloratus, more convex above, the spire shorter, 

 suture deep and umbilicus wider. Tawny-buff, with indistinct brown 

 spots. Alt. 73, diam. 55 mill. 



Bogota (Wallis). 



B. ampullaroides Mouss., Malak. Bl., xxi, 1873, p. 8. PFR M 

 Novit. Conch., iv, p. 132, pi. 130, f. 1, 2Conf., DOHRN, Jahrb. D. M. 

 Ges.,ii, 1875, p. 303, 304. 



This is regarded by Dohrn, evidently with justice, as an extreme 

 form of coloratus. It approaches P. gibbonius in size, but is com- 

 pletely distinct from that species in the shorter spire, greater con- 

 vexity of the whorls above, colored columella, etc. 



P. GIBBONIUS Lea. PL 33, fig. 46. 



Shell umbilicate, very ventricose, solid; chestnut-brown with 

 scattered darker spots, sparser on latter half of body-whorl. Sur- 

 face lusterless, irregularly ivrinkle-striate and densely granulated, 

 the granules readily visible to the naked eye. Spire slender. 

 Whorls 5, the first planorboid, sometimes wanting, the next minutely 

 vertically striate ; last whorl very rapidly enlarging, swollen. 



