1886.] 4JJ [Cope. 



Body and tail not prehensile ; nine normal head-shields. 



Ancistrodon* Beacv. 

 II. A rattle. 



Head with nine scuta above Crotalophorus\ Gray. 



Head with scales above Crotalus\ Linn. 



SYNOPSIS OF THE GENERA. 



Typhlopidse 6 Colubridse {continued) — 



Stenostomidae 2 Psammophidai 3 



Tortricidae 2 Lycodontinae 17 



Rhinophidae 7 Leptognathinae 7 



Xenopeltidae 1 Dipsadinoa 7 



Pythonidse 8 Dasypeltinae 2 



Boidse 16 Homalopsinae 30 



Charinida3 1 Acontiophidae 1 



Acrochordidae 2 Hydrophidai 8 



Nothopidae 2 Najidae .19 



Colubridas — Elapidae 3 



Calamarinae 58 Dendraspididae 1 



Coronellime 23 Causidas 3 



Scytalinae 18 Atractaspididae 1 



Colubrinae 36 Viperidae 7 



Philodryadinae 9 Crotalidae 12 



Dryophidinae 7 — 



Total 317 



A number of generic names have been given by authors with defini- 

 tions which do not refer to the dentition. On this account I have been 

 unable to include them in the above tables. I Lave credited generic 

 names to authors who have published the first description, and not to 

 those who have given them as nomina nuda. 



ERRATA AND ADDENDA. 



Page 486, middle, line 8, omit word "below." 



Page 486, below middle, line <J<J, for " first labial " read "internasals." 



Page 487, under Coronellin^e, immediately below line e insert a line, 

 viz : Two scale-pits ; rostral not produced Proterodon Hallow. 



Page 489, in character of genus Trimerorldnus, for "scale pores" read 

 " scale-pits." 



Page 490, above middle, immediately below line £ , insert a line, viz : 



Form robust ; tail moderate ; no scale-pits Grayia Gthr. ; 



also add the words "two scale-pits" to the characters of the following 

 genera — Coluber and Drymobius ; also remove synonymy of Coluber in 

 note %, excepting "Calopeltis Bp., " and piace it to the synonymy of 

 Grayia. 



* Cenchris Daud. 



iCaudisona Fitz, Wagl. ^rMrws Garman. 



% Caudisona Laur. Qrotalophorus Linn., pt., Uropsophus Wagl. 



PROC. AMER. PHILOS. SOC. XXIII. 124. 3L. PRINTED NOV. 1, 1886. 



