^ GONYOSTOMUS. 



Subgenus DRYPTUS Alb., 1860. 



Man. Conch, x, p. 37. Distribution, Venezuela and Colombia. 



The systematic position of this group cannot be regarded as fully 



settled. 



S. moritzianus Pfr., x, 38. S. marmoratus Dkr., x, 40. 



v. wilsoni Pils., x, 39. S. venezuelensis Nyst, x, 41. 

 S. indentatus DaC., xiv, 281. S. stubeli Mart., x, 42. 



S. guerini Pfr., x, 39. S. funcki Nyst, x, 42. 

 S. pardalis Fe>., x, 39. superbus Jonas. 



leptochilus Pfr. adoptus Rve. 



astropoides Jonas. 



Genus GONYOSTOMUS Beck, 1837. 



Man. Conch, x, pp. 96, 121. 



Shell rimate-umbilicate, fusiform or ovate-conic, rather thin, com- 

 posed of 5 to 5^ gently convex whorls. Surface finely granose in 

 spiral series. Aperture elliptic or ovate, angular above, rounded or 

 angular below ; the peristome evenly, narrowly expanded or retiexed. 

 Outer lip regularly arcuate, without callous projections within. 

 Columellar lip free, inserted high, the columella with a weak, 

 deeply placed fold. 



The foot (pi. 53, fig. 35, G. multicolor) is coarsely reticulated, the 

 tubercles being large and polygonal at the sides much smaller on the 

 dorsal surface of body and tail, three black stripes run parallel on 

 the back, parted by two slightly wider reddish bands which terminate 

 at the tentacles. The sole shows no trace of longitudinal division. 



Kidney much longer than the pericardium, projecting backward. 

 Ureter and secondary ureter open throughout, but represented by a 

 distinctly differentiated band. Reticulation of the lung almost 

 evenly spreading over both intestinal and cardiac sides, the vena cava 

 and pericardial vein each supplied with several large branches (pi. 

 49, fig. 8, G. multicolor, x 2). 



Free retractor system as in Bulimulidde, the pharyngeal retractor 

 being shortly connected with the left tentacular band, and the colu- 

 mellar muscle or tail retractor with the right band (pi. 54, fig. 37, 

 G. turnix, x 2). 



Genitalia (PI. 51, fig. 16, G. turnix, x 2 ; pi. 52, fig. 26, 

 G. multicolor, x 2 ; fig. 27, vagina of same), much as in Stroph- 

 ocheilus. The penis is long, cylindrical and fleshy, bearing the 



