Cope.] 486 [May 21, 



Scales keeled ; no preocular, two anals Haldea* B. & G. 



Scales keeled ; no loreal ; a preocular ; anal double Falconeria Theob. 



Scales smooth ; no preocular, two anals Farancia Gray. 



Scales smooth ; no loreal ; a preocular Pseudoeryxf Fitz. 



Scales smooth ; no loreal nor preocular ; one anal ; (? teeth) 



Calamophis Meyer. 

 XXX Two internasals ; one prefrontal. 



Rostral much produced Prosymna Gray. 



Rostral not produced, teeth equal Trimetopon Cope. 



Rostral not produced, teeth diacranterian Colorhogia Cope. 



XXXt Two internasals and two prefontals. 

 § Rostral plate reaching frontal. 



Nasals and first labial confluent Gyalopium Cope. 



§§ Rostral plate not reaching frontal. 

 a. Posterior maxillary teeth elongate. 



Two nasals well separated from preocular Arrhyton Gthr. 



Two nasals in contact with frenoocular Leptocalamus Gthr. 



aa. Teeth equal. 

 ft. Superciliary plate absent. 



Two nasals and a frenoorbital Colophryi Cope. 



ft ,3. Superciliary present. 

 y. Rostral plate produced. 

 d. Nasal plates distinct below. 



No loreal ; anal divided ; two nasals Geagras% Cope. 



A loreal ; anal entire ; two nasals Cemophora Cope. 



A loreal ; anal divided ; one nasal Chionactisl Cope. 



dd. Nasal plates united with first labial. 



A preocular and a divided anal Chilomeniscus\\ Cope. 



yy. Rostral plate not produced. 

 e. Palatine bones with teeth. 

 5j. One nasal plate ; one anal plate. 



Scales smooth Homalosoma^ Wagl. 



rjTj. One nasal and two anal plates. 



Loreal and preocular present Contia** B. & G. 



Loreal present, no preocuiar AbastorW Gray. 



Neither loreal nor preocular Oxyorrhos Fischer. :)::{: 



TjTjrj. Two nasal, one anal plate. 

 Maxillary bone very slender ; scales smooth ; a frenoorbital plate 



Stenog?iathm%% D. & B. 

 * Cotmcephalus D. & B. 



t Dimacles Gray. Calopisma D. & B. Hydrops Wagl. 

 %Eivulius Boc. Sphenocalamus Fisch. Pseudofldmia Boc. 

 § Lamprosoma Hallow. 

 || Brrgrnia Steindachuer. 

 % Rhabdium D. & B. 

 ** Cryptodacus Peters. Eirenis Jan. 



■ft Carphcphiops Gerv. Carph iphis D. & B. Celut t B. & G. 

 XX 187!) ; Atractocephahis Sauv. 1 1880. 

 llPldypleryx D. & B. 



