Cope.] *'o [Oct. 2, 



Leposoma reticulatum O'Sh. Leposoma guenUieri O'Sli. 



" picticeps Cope. " olivaceum Gray. 



" vertebrate O'Sh. " marmoratnm Gray . 



" schreibersii Wiegm. " poecilochilus L. & Von M. 



" bivittatum Cope. " metalticvm, Cope. 



" concolor Tsch. " bogotense~Pe[. 



" argulusVet. Proctoporus pacliyurus Tsch. 



" gaudicJiaudi~D. & B. " unicolor Gray. 



" affinisPet. " fraseri O'Sh. 



" maculatum Tsch. " oculatus O'Sh. 



" rhombiferum Gthr. " montium Peters. 



" acutirostre'Pet. " striatus Pet. 



' ' ocellatum Gray. ' ' luctuosus Pet. 



" strangulatum Cope. Emphrassiotis simoterus O'Sh. 



The species numher as follows : 



Mionyx , 1 



Iphisa 2 



Neusticurus 2 



Placosoma 1 



Leposoma 28 



Proctoporus 7 



Emphrassiotis 1 



Total ,42 



The characters of the genus Mionyx are the following : First toe of 

 both anterior and posterior extremities with rudimental straight claw ; 

 claws of other digits small, straight and conic. Prefrontal and fronto- 

 parietal plates present and distinct from each other. Ear-drum exposed. 

 No distinct collar. Femoral pores present. Pholidosis squamous, nearly 

 homogeneous. 



Char, specif. These resemble those of the group Leposoma within that 

 genus. The scales are imbricate and keeled, with acute posterior borders 

 above and below. When the epidermis is lost the inferior scales are nearly 

 truncate.* The dorsal and ventral scales are subequal and form twenty- 

 one transverse series between the anterior and posterior limbs, across the 

 back. Behind the auricular meatus, and in the axilla, they are coarsely 

 granular. The upper and lower arms are covered with large keeled 

 scales, although those of the posterior side of the former are smaller than 

 those on the anterior side. The hind leg is similarly surrounded by large 

 keeled scales, excepting on a band on the posterior side of the femur 

 where they are granular. 



There is a transparent disk of the lower eyelid, which is covered by 

 two scales. The plates of the head are smooth. There is a loreal plate 



* The truncation of the abdominal scales in the L. rwgiceps is seen in the epi- 

 dermis as well as the true skin. 



