424 bulletin: museum of comparative zoology. 



improbable the fact that they should arrive at, land upon, survive, 

 and reproduce their kind, upon some distant land, were they per- 

 mitted to essay this journey but once in a thousand years or even 

 less often. The enormous sum-total of species which make up the 

 fauna of the Antilles, and the many zoological groups which are repre- 

 sented upon so many of the islands alone refute the flotation theory. 

 If they did not we could lie-to in the mid-Caribbean and watch 

 the rafts go by, speculating as a pleasant game as to which bore 

 Onychophora and earthworms and which cyprinodonts or Amphibia, 

 wondering how the little ponds in the rafts in which the fresh water 

 fishes, molluscs, and crustaceans would have to be carried, are kept 

 from becoming a bit, only a bit to be fatally, brackish. So much for 

 the message of Ameiva with regard to the problem of the origin of 

 the Antillean fauna. 



KEY TO THE SPECIES. 



Caudal scales of adult oblique dorsally. 

 b' Nostril anterior to nasal suture. 



c' Three supraoculars, the first not in contact with the loreal. . .lineolata. 



c- Four supraoculars, the first in contact with the loreal maynardi. 



b^ Nostril between the nasal plates. 



d' Caudal scales smooth or feebly keeled, whorls not raised posteriorly. 



el Eight longitudinal rows of ventrals wetmorei, 



e^ Ten longitudinal rows of ventrals polops. 



d^ Caudal scales strongly keeled, the keels not parallel to the sides of 

 the scale, whorls raised posteriorly, 

 e' A single row of large postbrachials, two rows of tibial shields. 



f estiva. 

 e" Postbrachials small and irregular, three rows of tibial shields. 



ruthveni . 

 ■ Caudal scales of adult straight dorsally. 

 b' Nostril anterior to nasal suture. 



ci Fourteen longitudinal- rows of ventrals pluvianotata. 



c^ Less than fourteen longitudinal rows of ventrals. 

 d^ Twelve longitudinal rows of ventrals. 



el Gular scales minutely granular, a broad band of enlarged granules 

 extending across the throat, 

 fi Tibial shields with largest scale of outer row broader than high; 



pale spots on body not confluent pleii. 



f^ Tibial shields with largest scale of outer row about as broad as 

 high; pale spots of body confluent garmani 



