180 Zoological Society : — 



less dangerous animal than C. lanceolatus. The frequent occurrence 

 of the bite of C. atrox is easily accounted for, as it is commonly met 

 coiled up in the middle of footpaths, and is not easily disturbed un- 

 less trod upon. Neither C. lanceolatus nor C. brasiliensis have as 

 yet been observed by me. Of the scarce C. bilineatus I have only 

 seen two specimens ; but I hear that six specimens have been found 

 together in the colony Leopoldina, near Ilheos. I shall refrain from 

 making any further remarks on this genus until 1 shall have col- 

 lected more specimens for comparison than I at present possess. All 

 my specimens of C. atrox differ from those described by herpetolo- 

 gists in having fewer longitudinal series of scales (23-25). 



Lachesis mutus is far from being scarce. The largest specimen I 

 have seen measured 10 feet. 



Crotalus horridus is chiefly an inhabitant of the interior of the 

 province, but is not very scarce on a row of hills which extends 

 through the city of Bahia. In some parts of the province (for in- 

 stance in Ilheos) it has, according to trustworthy testimony, never 

 been seen. 



Of the family Fiperidce, the only species, according to Dr. Gray, 

 which is found in the "Western World is Peruvian. 



Of the numerous freshwater species of the family of Hydridae few 

 representatives seem to occur in the Brazils, Helicops angulatus 

 being perhaps the most common species in this province. A second 

 species, Helicops Leprieurii, Dum. et Bibr., still appears to be scarce 

 in the collections. Perhaps a description taken from fresh specimens 

 may facilitate its identification. 



Diagnosis. — Head ovate, short ; three frontals, anterior trigonal, 

 between the nasals ; labials entire ; superciliaries large, almost of the 

 length of the vertical ; vertical elongate ; loreal distinct ; one or two an- 

 terior and two posterior oculars ; occipital s elongate ; body fusiform ; 

 scales in nineteen rows, truncated, polished, smooth, those of the 

 middle and hinder part of the back and of the tail keeled ; tail di- 

 stinct, tapering. 



Description. — Head ovate, flat on the vertex, not very distinct ; 

 cleft of mouth moderate ; eyes superior, moderate, pupil round ; 

 three frontals, anterior small and almost triangular (irregularly qua- 

 drangular, with an obtuse posterior angle) ; nostrils superior, between 

 two nasals ; vertical moderate, elongate, with the lateral edges parallel 

 or slightly divergent posteriorly, rectangular behind ; occipitals 

 large, elongate ; eight upper labials, entire, the seventh much larger 

 than the rest, fourth and fifth reaching to the eye, rostral broader than 

 high, its upper angle very obtuse ; series of teeth of moderate length, 

 posterior tooth longest, grooved, anterior all equal ; body fusiform ; 

 tail distinct, rather short, tapering ; scales moderate, truncated be- 

 hind, poHshed, in nineteen rows, those of anterior part and of sides 

 of body smooth, of posterior part and of tail keeled ; no scales of 

 the middle line in any part larger ; ventral shields narrow ; anal 

 divided ; subcaudals in two rows. 



Above olive, with three darker longitudinal streaks, or rows of 

 spots sometimes confluent, alternating in the different rows ; inferior 



