280 iniiwls State Lahoratory of Natural History. 



No aateorbitals. Two postorbitals. Body moderately stout. 

 Head scarcely distinct from the body. 



Two internasal plates. With several longitudinal red stripes 

 above H. erythrogrammus. 



One internasal plate. Uniform blue black above. 



H. ABACURU8. 



Hydrops erythrogramnius, Daudin. Red-lined Horned 

 Snake, Hoop Snake. 



Co/ H her ertithro(jr<uninns, Daudin, Hist. Nat. Rept., 1799, VII., 



p. 93, pi. 83, fig. 2. 

 Ihlicops <r>/t/ir<>i/r((iiinins. Holbr., N. A. Herp.. 1842, III., p. 107, 



pi. 25.' 

 Ahasior <-i!it]iro(jntiiniiiis. Ud. and Gir., Cat. N. A. Rept., Pt. I., 



1853, p. 125. 

 ('(ilopisiiiii t^rythroiirdiiniiiis. Dum.et Bibr., Erp. Gen., 1854, VII., 



p. 336. ' 

 Aha.stor truth lograiniHiis. Davis and Rice, Bull. 111. State Lab. 



Nat. kist, I., No. 5, 1883, p. 32; Bull. Chicago Acad. Sci., 



1883. 

 Hjidrups trythroyrKiiimus. IS. Garman, Mem, Mas. Comp. Zotil., 



1883, pp. 35, 144. 



Body moderately stout. Head scarcely wider than the 

 neck, slightly depressed. Tail short. Dorsal scales smooth. 

 Rostral plate very wide. Two small internasals. Prefrontals 

 large, forming part of the anterior rim of the orbit. Frontal 

 plate hexagonal, its lateral margins nearly parallel, except 

 between the parietals. Supraciliaries large. One nasal plate, 

 grooved below the nostril. Loreal elongate, forming part of the 

 anterior rim of the orbit. No anteorbital. Two postorbitals, 

 the lower small. Supralabials seven, sixth largest. Infrala- 

 bials seven or eight, the fourth or fifth largest. Dorsal scales 

 in nineteen rows, all smooth and polished. Ventrals 167-185, 

 Subcaudals in :}8-50 pairs. 



Color above bluish black, with five longitudinal red stripes. 

 Of these, one on each side occupies the two outer rows of scales, 

 excepting the bases of the scales of tlie inner row; three 

 scales above these stripes, on each side, is another, occupying but 

 one scale in width: while the fifth stripe occupies the median 

 dorsal row of scales. Beneath carneous, with round black 



