ORTHALICIN^E. 99 



Aside from some resemblance to Oxychona pileiformis, already no- 

 ticed by Dohrn, this species resembles no other South American 

 snail, though it is obviously related to D. cinnamomeolineatus and 

 its allies. Out of nine specimens before me, two lack the reddish tip 

 at the apex, and one has a light red line bordering the suture below, 

 and about 1 mill. wide. As Dohrn remarks, the whorls vary in con- 

 vexity in different specimens. He gives the following measurements 

 of the largest and smallest specimens: Alt. 30, diam. 13, length of 

 aperture 13 mill.; alt. 19, diam. 10, length of aperture 10 mill. The 

 soft parts are said to be light green with yellowish sole. 



On the authority of Paz, Hidalgo records this species from Rio 

 Janeiro ; but I am disposed to believe that some one in that city gave 

 or sold it to Paz with a number of other north Brazilian snails. 

 There is no sufficient evidence to show that any Leiostracus occurs 

 living in the province of Rio Janeiro. 



Subfamily ORTHALICIN.E. 



Shell varying from ovate to oblong-conic, wholly imperforate, with 

 solid axis, the aperture ovate, toothless, columellar lip closely ap- 

 pressed, the lip-ends distant. 



Jaw composed of about 15 broad plates, overlapping or imbricating 

 as usual in BidimulidfE, the median plate usually subtriangular. 

 Radula peculiar, the basal-plates short, oblong or quadrate, the 

 cusps short and blunt or rounded, gouge- shaped throughout, or a few 

 median teeth have pointed cusps : no division into ectocone, entocone 

 and mesocone except on the marginals, where it is not strongly indi- 

 cated. 



Genital system simple, except that there is a small appendix or 

 accessory gland about midway on the penis, rarely replaced by a cir- 

 cular swelling. No flagellum. 



Oviparous. The eggs are elliptical, brown or whitish, and rough- 

 ened by distinct granules. 



Distribution : tropical and subtropical America. Most of the spe- 

 cies live on trees and bushes, but probably Hemibulimus and part of 

 Orthalicus s. str. are terrestrial. 



This subfamily differs from the Su/imttlince in the imperforate, not 

 even rimate shell, the broad plates of the jaw and their small num- 

 ber, the highly modified, gouge-shaped teeth, and the presence of an 

 appendix on the penis. It is a very natural group, comprising several 

 quite closely-allied genera. 



