564 REPORT OF NATIONAL MUSEUM, 1902. 



7. Typhlops Ivmhricalis. 



8. Epicrates moner&is. 



9 . Alsophis portoricensis. 



These also show a mixture of types. Alsophis portoricensis is typ- 

 ical Porto Rican; Sphserodactylits monensis, Ameiva alboguttata, and 

 Anolis m on < nsis, although described as separate forms, are very closely 

 allied to Porto Rican species; Mahuya sloanii occurs both in Porto 

 Rico and Haiti; Eleutherodactyl/as monemis and Epicrates monensis are 

 most nearly related to Haitian species, while CycJura cornuta is typ- 

 ically Haitian, the genus even being unknown in Porto Rico; Typhlops 

 lumhricalis is of wide distribution, as shown above. The herpetolog- 

 ical fauna of Mona is consequently exactly intermediate between Porto 

 Rico and Haiti, as is its geographical position. 



The herpetological relations of Porto Rico to the Virgin Islands 

 immediately to the east is very close, as might be expected, located, as 

 they are, within sight of each other and on the same bank limited by 

 the 100-fathom line. St. Croix, which is separated b} T a deep channel 

 from the others, is also more distantly related, possessing, as it does, 

 several species not found in the Virgin Islands proper, much less in 

 Porto Rico, namely, Thecadactylus rapicauda (possibly accidentall} 7 

 introduced), Anolis acutus, Ameiva polops, and Alsophis sancti-crucis. 



If we compare the fauna of Porto Rico with that of St. Thomas and 

 St. John more in detail, we will find that the chief difference lies in the 

 absence in the latter of a great number of species occurring in the 

 former, as will be seen from the following: 



List af Porto Rican species (") not found in St. Thomas or St. John. 



1. Bufo lemur. 



2. Eleutherodactylus auriculatus. 



3. Eleutherodactylus richmondi. 



4. Eleutherodactylus wnicolor. 



5. Sphserodactylus grandisguamis. 



6. Celestus pltii. 



7. Anolis curie ri. 



8. Anolis gundlach i. 



9. Anolis evermanni. 



10. Anolis krugi. 



11. Anolis poncensis. 



12. Amphisbsena cxca. 



13. Amphisbsena bakeri. 



14. Typhlops rostellalus. 



15. Epicrates inornatus. 



16. Leimadophis stahli. 



17. A I soph is portoricensis. 



It will be seen that the existence of many of these species in Porto 

 Rico is not due solely to the fact that it is much the larger island, but 

 also to its more western location and more intimate relation to the 

 other large Antilles. On the other hand, some of the species in 

 this list are represented in the Virgin Islands by very closely related 

 forms. 



« Excluding those found in Mona Island, 



