Q7 



1885.] '" [Cope 



characterization of tangible divisions. On the other hand, Professor Peters 

 quite overlooked important characters of the squamation of the head, such 

 as are usually found to distinguish natural genera in other families, includ- 

 ing them only in his descriptions of the species. I propose to give a syn- 

 opsis of the genera of this group as they appear to me. One result is a con- 

 siderable reduction in the number of names. Agreeing with Dr. Boulen- 

 ger that these species do not form a family distinct from the Teidse, I 

 define them as a group in that family with the nostril pierced in a single 

 plate. 



I. " Thumbs without claws." 



A series of scuta on the nape ; frontonasal and frontoparietal scuta present. 



Iphisa Gray. 



II. Claws all straight, conic. 



No nucleal scuta ; frontoparietals and frontonasals present. .Mionyx Cope. 



III. Claws curved, present on all digits. 

 a. Dorsal series of large scuta. 



Scuta in separate longitudinal series ; forming keels on the tail 



Neusticurus D. & B. 



Scuta continuous, transverse ; frontonasal and frontoparietal scuta 



Placosoma Tsch. 

 aa. No larger series of dorsal scuta. 



Frontonasals and frontoparietals present Leposoma Spix. 



Frontoparietals, but no frontonasals Proctoporus Tsch. 



No frontoparietals or frontonasals Emphrassiotis O'Sh. 



In the above arrangement there is included, under Iphisa, Perodactylus 

 R. & L. Leposoma includes nearly all the reputed genera of Peters 

 and other authors, viz : Loxopholis Cope : Cercosaura "Wagl. ; Pantodac- 

 tylus D. & B. ; Ecpleopus D. & B. ; Aspidolmmnus Pet. ; Euspondylus Tsch. ; 

 Aryalia Gray (Peters) ; Chalcidolepis Cope ; Xestosaurus Pet. ; and Pris- 

 tidactylus O'Sh. Proctoporus Tsch. includes Pholidobolus Pet., Oreosaurus 

 Pet., and species referred to Ecpleopus by O'Shaughnessy. Of the species 

 referred to the group Leposoma, as originally restricted, but two have the 

 abdominal scuta acute posteriorly, viz : the L. scincoides Spix, and the L. 

 carinicaudatum Cope. The other species referred by O'Shaughnessy and 

 Peters to that group have, according to them, the abdominal scuta trun- 

 cate posteriorly, and must hence be referred to the group Loxopholis Cope, 

 of which L. rugiceps Cope is type. These are the L. dispar Peters, and L. 

 buckleyi O'Sh. The species thus arranged will be as follows : 



Mionyx parietalis Cope. Leposoma carinicaudatum Cope. 



Iphisa elegans Gray. " rugiceps Cope. 



'* modesta R. & L. " dispar Pet. 



Neusticurus bicarinatus L. " buckleyi O'Sh. 



ecpleopus Cope. " ocellatum Wagl. 



Placosoma cordylinum Tsch. " humile Pet. 



Leposoma scincoides Spix. " olivaceum Gray. 



PROP. AMER. PHILOS. SOC. XXIII. 121. M. PRINTED NOVEMBER 7, 1885. 



