Species o/Uruguaya, Carter. 5 



the spicules is distinctly micropunctate, but this is scarcely 

 visible unless they are magnified about 300 diameters. 



Gemmules are present in the lower portion of the sponge 

 attached to the surface on which the sponge grows ; as in 

 U. rejmis they are aggregated together into small monticules, 

 from two to five in each. The monticule is enclosed by a 

 common outer envelope of curved cylindrical spicules of far 

 smaller proportions than those of the skeleton. The gem- 

 mules are subglobular and furnished with a coating of amphi- 

 disc-spicules of a similar form to those of U. repens^ but of 

 slightly different proportions. 



This species is based on a large bushy specimen, nearly 

 entire, which is now preserved in the British Museum. It 

 was presented by Mr. MacAndrew, and is labelled as coming 

 from Paraguay. The specimen has been studied by Mr. 

 H. J. Carter, F.R.S., who regarded it as identical with U. 

 coralUoides, Bowbk., and, in fact, Mr. Carter's own description 

 of this last-named species appears to have been mainly de- 

 rived from the characters of this specimen. There are, how- 

 ever, distinct differences between this and the type of Bower- 

 bank's species which seem to me to be of specific value. 



The Paraguay specimen is attached to a large pebble, 

 which it almost entirely covers with a firm thin crust, from 

 which the stems and branches rise to form a rigid bushy 

 mass, which is about 200 millim. in height, the same in 

 width, and 90 millim. in thickness. The branches, when 

 simple, are nearly circular in cross section and about 5 mil- 

 lim. in thickness ; they have a tendency to coalesce laterally 

 to form semipalmate expansions. Occasionally small patches 

 of a smooth dermal membrane are preserved. The spicules 

 of the surface of the lower portions of the sponge are so 

 closely arranged as to form a crust in which no apertures can 

 be recognized ; in the upper portions there are irregular 

 interspaces in the surface-layer leading into the interior, as in 

 U. repens. 



The oscules are, as a rule, nearly level with the general 

 surface of the sponge, sometimes they have slightly elevated 

 margins ; they are from ] to 2 millim. in width, a few simple 

 oscules are, however, only "5 millim. across. The skeleton- 

 spicules are from "25 to '34 millim. in length and from '03 to 

 •04 millim. in thickness. The acerate spicules are about 

 half as thick as the cylindrical forms ; they are very few in 

 comparison with these latter. 



The gemmules appear to be few in number, and, as in U. 

 repenSy they are attached to the substance on which the sponge 

 is growing and are overgrown by the base of the sponge. 



