366 OPHIDIA. 



30 ft. ; P. molurus L., India and Ceylon, to 30 ft. ; Trachyboa Ptrs., 

 S. Amer. ; Ungalia Gr., W. Indies, Guatemala, Ecuador, Peru ; Ungaliophis 

 F. Miill., Guatemala. 



Fam. 4. Ilysiidae. Cranial bones are more or less solidly united ; 

 ventral scales hardly enlarged ; teeth and pelvis as in the last. Ilysia 

 Hemp., S. Amer. ; Anomalochilus Jeude, Sumatra ; Cylindrophis Wagl., 

 Ceylon and S.-E. Asia. 



Fam. 5. Uropeltidae. Burrowing snakes of small size, restricted to 

 Ceylon and S. India. Cranial bones solidly united, pterygoid not reaching 

 quadrate, with ectopterygoid, without squamosal ; eye small ; tail short 

 ending in a large shield. Uropeltis Cuv., Ceylon; Rhinophi's Hemp., 

 Ceylon and S. India ; Silybura Ptrs., India, Ceylon ; Pseudoplectrurus 

 Blgr., S. India ; Plectrurus S. India ; Melanophidium Gthr., S. India ; 

 Plat yplectr urns Gthr., S. India. 



Fam. 6. Xenopeltidae. Cranial bones more or less solidly imited ; 

 ectopterygoid present, pterygoid reaching quadrate, squamosal present, 

 prefrontal in contact with nasal ; teeth in jaws, palate and premaxillary ; 

 mandible without coronoid ; dentary moveably articulated to the articular ; 

 tail short ; a single genus and species Xenopeltis (Tortrix) unicolor 

 Reinw., in S.-E. Asia. 



Fam. 7. Colubridae. Facial bones moveable, prefrontal not in contact 

 with nasal, ectopterygoid present, pterygoid extending to mandible or 

 quadrate, squamosal present, maxillaries horizontal, mandible without 

 coronoid, both jaws and palate toothed ; 242 genera, cosmopolitan, with 

 terrestrial, arboreal and aquatic forms. The family is divided into 3 series. 

 Series A. Aglypha — All the teeth solid, not grooved. Series B. 

 Opisthoglypha. — One or more of the posterior maxillary teeth grooved. 

 Series C. Proteroglypha. — Anterior maxillary teeth grooved or perforated. 



Series A. Aglypha. 

 The Aglypha are harmless non-poisonous snakes and are divided into 

 3 subfamilies. 



Sub-fam. 1. Acrochordinae. The postfrontal bone produced over 

 the supraorbital region ; scales not or but slightly imbricate ; S.-E. 

 Asia and C. Amer. ; many species are aquatic in rivers and estuaries. 

 Acrochordus Hornst., Malay P. and Arch., N. Guinea ; Xenodcrmus 

 Reinh., Java, Sumatra, Penang ; Chersydrus Cuv , mouths of rivers 

 and coasts of S.-E. Asia and Papuasia ; StoUozkaia Jerd., Khasi 

 Hills, N.-E. India ; Nothopsis Cope, C. Amer. 



Sub-fam. 2. Colubrinae. Postfrontal bones not produced over 

 the supraorbital region ; scales usually imbricate ; teeth on the entire 

 length of the maxillary and dentary bones ; cosmopolitan, but scarce 

 in Australia. The sub-family contains about 1 ,000 species, and the 

 genera may be arranged in two groups according to the presence or 

 abs3nce of hypapophyses on the posterior dorsal vertebrae. 



I. Genera which have the hypapophysis on all the vertebrae, 

 arranged alphabetically. 



Ablabophis Blgr., S. Afr. ; Achalinics Ptrs., China, Japan ; 

 Amphiardis Cope, Texas ; Aspidura Wagl., Ceylon ; Blythia Theo., 

 Khasi Hills ; Boodon Gthr., trop. and S. Afr. ; Bothrolycus Gthr., 

 W. Afr. ; Bothrophthalmus Ptrs., trop. Afr. ; Brachyorrhus Boie, 

 Malay Arch., N. Guinea ; Chersodromus Reinh., Mexico and Guate- 

 mala ; Cyclocorua D. and B., Philippines ; Compsophis Mocq., Mad. ; 



