8 Dr. G. J. Hinde on some neio 



example of U. corallioides presented to the Liverpool Free 

 Museum by his brother, Mr. George Higgin, C.E,, but 

 could not discover gemmules in it. 



This species is closely related to U. Macandrewi in its 

 mode of growth, but differs therefrom in the simple form and 

 linear arrangement of the oscules, in its compressed branches, 

 and in the more robust proportions of the skeletal spicules. 

 From the Congo forms of tiruguaya it is distinguished by 

 its mode of growth and by the simple character of the oscules ; 

 the spicules, moreover, are not so long as in the African 

 forms, but they are equally robust. 



Distribution. River Uruguay^ near Salto, Banda Oriental, 

 South America. Mr. Carter has already pointed out Dr. 

 Bowerbank's error in stating that this Salto was on a branch 

 of the Amazons. The type form is in the museum of the 

 Royal College of Surgeons ; a branch from it, which belonged 

 to the Bowerbank collection, is in the British (Natural His- 

 tory) Museum. 



Uruguaya pygmcea^ sp. n. (PI. IV. figs. 7-10.) 



Sponges minute, simple or compound, subconical in form, 

 with a slightly expanded base, of a light brown or silvery- 

 white tint in the dried state, with one or occasionally two 

 simple oscules. The sponge is built up of minute, smooth, 

 arcuate, cylindrical spicules with rounded ends, which form a 

 smootli outer crust with microscopic interspaces, Gemmules 

 subglobular in form, furnished with spool-like amphidiscs, 

 with incurved margins, like those of the other species of the 

 genus. 



This species is founded on some very small sponges grow- 

 ing at the base of the type specimen of U. Macandrewi, 

 described above. In most instances the sponges are partially 

 attached to the outer surface of the larger form, in others 

 they grow entirely separate from it on the surface of the 

 pebble on which the larger form likewise grows. In the 

 cases where the minute sponges grow partially on the surface 

 of U. Macandreioi they are attached to the surface-membrane 

 of this form and thus evidently exterior to it. The sponges 

 are nearly circular in outline at the base, from 2 to 5 millim. 

 in width, and from 'lb to 1*5 millim. in height. They are 

 generally simple, with a single well-defined oscule from '2 

 to "5 millim. in width at the summit ; in some examples two 

 oscules are present. The sponge apparently consists of a crust- 

 like wall, enclosing an interior spicular mesh. The spicules 

 are very uniform in size, measuring '11 millim. in length by 



