Verrill, Notes o?i RacUata. 



347 



CARIBBEAN FAUNA. PANAMIAN FAUNA. 



Stirhopus riciidns Sel. Stichopns Kefersteinii Sel 



Florida, Zanzibar, etc. Acapulco. 



S. bidionolus Sel. 



" Florida (Acapulco ?)" 

 Actiriopyaa [Mk Ueria) 2^ffi'vula (Sel.sp.) 



Florida. 

 A. {M.) Af/assizii (Sel. sp.) 



Florida, Tortugas, Hayti. 



A. (M.) ohsc'ira (LeS. ?p,) 

 St. Bartholomew. This and the next two 

 species may prove identical with some of 

 the preceding. 



Bohadschia agglutinota (LeS. sp.) 

 St. Bartholomew. 



B. ff'Sciata (LeS. s[).) 

 St. Bartholomew. 



Sporadipus ffigas Orst. ! 

 Perhaps identical with one of the preced 

 ing species. 



These lists contain 125 species from the Caribbean, including a few 

 that are marked as doubtful, and 82 from the Panamian Fauna. Of 

 these none have ever been indicated as common to the two coasts, ex- 

 cept two species of Holothurians which Selenka records from both 

 coasts, and another [Sticho2yus hadionotus Sel.) from Florida and, 

 doubtfully, from Acapulco. The Holothurians being very difficult to 

 identify with alcoholic specimens, it is not improbable that these few 

 apparent exceptions to the rule among the Echinoderms will prove 

 to be errors in determining the species. In the other orders the spe- 

 cies are often very closely allied in structure and appearance, yet the 

 differences are in all cases sufficiently apparent. There are, however, 

 so many analogous or representative species in the two faunas, and so 

 general an agreement in the genera and families represented, that the 

 general features of the faunae have a remarkable similarity, while they 

 stand in strong contrast with the tropical fauna of the Pacific and 

 Indian Oceans. 



In this respect the Echinoderms agree with the observations, previ- 

 ously made upon the Crustacea and Mollusca, and confirm the state- 

 ment that both coasts of America belong to one grand Zoological 

 Realm, in distinction from all other regions, and that America has 

 therefore a remarkable insular character, and may be regarded zoo- 

 logically as a great " Island in the Atlantic Ocean," the deep oceanic 

 basin west of the Galapagos limiting the western extension of the 

 American or Atlantic forms. 



Among the types peculiar to the American Realm the genus Ophi- 

 ura is one of the most remarkable instances, since it abounds on both 



