Verrill, Notes on Radlata. 339 



The Araucaxiax Province — This appears to extend from near 

 Valdiva to the south-western coast of Patagonia, but its southern 

 portion is very little known. Dana places its southern boundary at 

 lat. 50°, which would make its length about 900 miles. 



The Fuegian Province. — This includes southern Patagonia and 

 the adjacent Islands. Several pecul^r and interesting Echinodex'ms 

 have been described from this Fauna, some of which, as Asterias 

 antarctica and " Guvleria antarctica,^'' recall 'the forms of the Arctic 

 regions, while there are other genera, as Trlpylus^ that are quite 

 peculiar. 



Comparison of the Tropical Echinoderm Faunm of the East and 

 West Coasts of America. 



Tlie question of identity between certain species found upon the 

 Atlantic and Pacific coasts of Central America is of great interest 

 both to the Zoologist and Geologist, and has received much attention 

 from various writers. That the two FauniB are remarkably similar 

 in many respects, and have large numbers of closely allied, repre- 

 sentative or analogous species, is admitted by all who have written 

 upon the subject. Several authors also admit a certain number of 

 species which are identical or undistinguishable. Thus of Mollusca, 

 Dr. P. P. Carpenter* admits 35 species as identical between the two 

 coasts; 34 additional ones that may prove to be identical ; 41 that 

 are " really separated, but by slight differences ;" 26 that are " analo- 

 gous but quite distinct species." In addition to these he admits 15 

 species as probably common to the west coast of America and the 

 west and south coasts of Africa. Prof C. B. Adamsf did not admit 

 any species as common to Panama and the West Indies, except 

 Crepidula unguiformis. 



Prof Dana, Dr. Stimpson,J and others admit several species ol 

 Crustacea as common to the two coasts. In the collections of Mr, 



* Report of the British Association for tlie advancement of Science, 185(3. 

 \ Annals of the Lyceum of Natural History of New York, v, 1852. 

 \ Notes on North American Crustacea. Annals Lyceum Nai. Hist, of N. Y., 1858 

 and 1860. In these papers the following species are indicated from both coasts : 

 Petrolisthes armatus Stimp. Cronius ruber Stimp. 



Ozius peiiatus atimp. Nautilograpsus minutusW. Edw. 



Uriphia gonagra 'M. Edw. Acanthopus planissimus Baiia. 



Oallinectes diacanthus Stimp. Domecia hispida Souly. 



Mr. Albert Ordway has satisfactorily separated the western species of Oallinectes 

 from those of the West Indies, (Boston Journal Nat. History, vol. vii, 1863). Concern- 

 ing some of the other species Dr. Stimpson, himself, expresses doubt, owing to the 

 want of sufficient specimens for ascertaining the constancy of slight differences. 



