THE GORGONIANS OF THE BRAZILIAN COAST. 375 



Instead of being entirely horn-like and flexible, as in the West Indian species, 

 they have the axis more rigid and partially calcareous, so that it effervesces f eebly 

 in acids, as in some GorgoneUidce. This shows that this character alone i u 1> 

 sufficient to separate the families. In fact, some of the Brazilian species of 

 Leptogorgia might be considered as connecting links between the families, in thi> 



respect. 



Another interesting morphological feature has been found to be highly 



developed in all the several Brazilian species of PlexaureUa. Though not 

 confined to the Brazilian species, they show it more prominent 1 developed than 

 in others. Reference is made to the elaborate system of tubul* permeating 

 the ccenenchyma in all directions and rendering it cellular, some of them con- 

 necting with the exterior by special pores, evidently to permit the five di harge 

 or intake of water during rapid contraction and expansion of the large polype, 

 as well as for distribution of nourishment. (See below, under suhfamily Pier- 

 aurellince, Plate XXXV, figures 14, 15.) 



GEOGRAPHICAL DISTRIBUTION. 



Most of the species here included occur in the coral-reef region of Brazil, 

 extending from somewhat north of Pernambuco, or about S. Lat. 7°, to the 

 Abrolhos Reefs and Porto Seguro, or to about 18° S. Lat. But some of the 

 gorgonias, like some of the corals, have a wider range, extending southward 

 beyond the actual coral-reefs to Victoria Bay, and even to Cape Frio, about 

 S. Lat. 23. Such species, therefore, have a range of about 16 degrees or ov r 

 1,000 miles. Among those having a wide range are Phyllogorgia quercij < >lia , 

 which is known to extend from Bahia to Cape Frio; Muricea humilis, ranging at 

 least from Parahiba to Guarapary; and PlexaureUa, cylindrical, from Bahia to 



Cape Frio. 



Very likely all the reef-inhabiting species extend at least as far north and 



south as do the coral reefs 



Unfortunately we know almost nothing of the corals and gorgonians inhabiting 

 the long stretch of coast between Pernambuco and the Antilles, a distance of 

 over 2,000 miles. Therefore it is impossible to say whether the coral fauna of 

 the Antilles extends to the southward of the Orinoco River at any point. Nor 

 is it possible to say, at present, whether any of the corals and gorgonians extend 

 on the northeastern coast of Brazil, beyond Maranhao, from whence we now 

 have two new species of gorgonians not known from any other place. 



From south of Cape Frio we have two species of Leptogorgia in t he Bay of 

 Rio de Janeiro. This genus, in other regions also, is apt to extend into the 

 temperate waters beyond the areas of coral reefs. One gorgonian species, 

 PlexaureUa obesa. comes from Fernando des Norhona. 



i 



and 



190-214 



Amer 



,un, Proc. Boston Soe. Nat. Hist., XX, pp. 39-41 

 Also J. D. Dana, Corals and Coral Island*, ed 



1890 



