Verrill, JVofes on Radiata. ,385 



He sub-divides the genus, however, into three groups, as follows : 



1. Sjjecies having only spindle-shaped spicula. 



2. Species having spindles and bracket-shaped spicula (Klanimern), 



3. Species having spindles, and in a peculiar external layer, singu- 

 lar club-shaped spicula. 



The last group contains G. verrucosa and closely allied species, and 

 corresponds partly with Gorgoyda as restricted by Milne Edwards. 

 It appears to be a very natural and well-delined group, approaching, 

 by its smooth external layer composed of clulvshaped spicula, the 

 genus Eimicea. All the ascertained species belong to the Mediter- 

 ranean and African coasts.* 



The second section is also a natural and clearly defined group, cor- 

 responding to a great extent with Gorgonla and Pterogorgia of 

 Ehrenberg, though a few species of the latter go into the first section 

 (P. sarmentosa and P. petechizans). It includes the typical species 

 of Pterogorgia, Xiphigorgia, and Hymenogorgla of Edwards and 

 Haime, and two species of Leptogorgia, as well as the type of PJd- 

 pidogorgia Val. [R. flabellum). All the species, so far as knoAvn to 

 me, are Atlantic, and nearly all are confined to the West Indies and 

 Atlantic coasts of North and South America, not one having yet been 

 found upon the Pacific coast of America. 



The first section, however, appeai-s to include several natural groups, 

 two of which appear quite as distinct as the two preceding. Among 

 the species enumerated by Dr. Kolliker are several species referred by 

 Edwards and Haime to Gorgo)da, Rhipidogorgla, Gorgonella, Lep- 

 togorgia, Pterogorgia, and the typical species of Lophogorgia. 



The numerous species of Gorgonim from the west coast of Amer- 

 ica, would all fall into the first of Dr. Kolliker's sections, but among 

 them there are two well-defined groups, characterized best by pecul- 

 iarities of the spicula, each including numeroiis species. 



In the first of these divisions the spicula of the coenenchyma are 

 mostly small, warty or papillose double-spindlesf of two kinds, — a 

 longer and more slender sort, mingled with those that are shorter and 

 thicker. {TJtigorgia V.). 



In the second division there are, in addition to the two forms of 

 double-spindles, a large number of " double-wheels," or short s])icula 



* G. papulosa Esper, formerly supposed to be from the East Indies, was collected at- 

 the Cape of Good Hope by the United States Exploring Expedition (CoU. Smithsonian 

 Inst, and Yale Museum). 



f Those spicula having a fusiform shape, more or less pointed at the ends, with a 

 'narrower and usually smooth space in the middle, are termed "double-spindles" (Dop- 

 pelspiudeln) -by Dr. Kolliker. Those without the median constriction are '' spindles." 



