THE GORGONIANS OF THE BRAZILIAN COAST. $83 



plates. In this case they seem to be very simple siphonozooids. In Pkmurella 

 they may be only a more rudimentary or degenerate variety, without meet uteris*. 



To determine whether they have a distinct zooidal structure would require 

 specimens carefully hardened and prepared in alcohol, such as I have not seen. 



The present writer first determined the zooidal nature of the external pores 

 in ReniUa f in 1864 (Revis. Polyps, p. 12), and in several other PennatuUicca an 

 in Sarcophytum , in 1865, and subsequently in various other genera. 



They are rare in Gorgonacea, but are well developed in Paragorgia. They 

 exist in Iridogorgia, and some other genera of deep-sea Chrysogorgida, and in 

 Anthomastus, etc. Those of Astrogorgia have not been hitherto mentioned. 

 (See also Kolliker, Pennatuliden, I, p. 37, 1870.) 



The most obvious distinctive characters for this subfamily arc th< nail 

 sizes of the spicules and the unusual abundance of regular and irregular cron 

 or twinned forms among the spicules. These are often among the larger and 

 more conspicuous forms. The axis contains fusiform strands of calcium carbo- 

 nate, so abundant that it effervesces freely in hydrochloric acid. 



This genus is unusually well developed on the Brazilian coast and in the West 

 Indies. 



Subgenus PSEUDEUNICEA nov. Type, P. grandifiora V. 



Most of the Brazilian species belong to typical PUxaurella. A single pecicp 

 differs sufficiently to be regarded as representing a subgeneric group. It* 

 principal characteristic is the large, prominent, exsert calicles, with the apertun 

 bilabiate. In this respect it resembles certain West Indian species of Eunicea, 

 but the spicules are like those of typical PlexaureUa, with which it also agrees 

 in the tubules permeating the coenenchyma and having external openings. 



The prominence of the calicles cannot be regarded as of very great importance 

 in this group, for P. verrucosa, which usually has them verruciform, sometimes 

 bo contracts that they scarcely rise above the level of the coenenchyma. Th< 

 amount of elevation is also quite variable in P. dichoioma of the West Indies 

 and Bermuda, according to the suddenness of killing; those killed quickly by 

 sudden immersion in some reagents may die before much contraction can take 

 place. 



PlexaureUa obesa Verrill, sp. nov. 



Plate XXXI, figure 3 (general figure of No. 4509, reduced). Plate XXXII. 

 figure 9 (calicles enlarged). Plate XXXIV, figure 6 (spicules of the same). 



Coral dichotomous, with few very stout, elongated, obtuse branches, of 

 which there are only four in the type. The branches are much thicker than 

 the main stem. They increase gradually in size from the base for a short distance 

 and then become cylindric, or they may be somewhat flattened. The tips arc 



obtuse or abruptly rounded. 



Total height, 240 mm. ; breadth, 70 mm. ; length of longest branch, 150 mm. ; 



diameter in middle. 22 mm. : diameter of stem, 8 to 12 mm. 



