164 BRITISH PALAOZOIC SPONGES. 
42. HoLasTERELLA CoNFERTA, Carter. Plate VIII, figs. 2, 2 a—2 g. 
1879. HotasTeRELLA ConFERTA, Carter. Ann. and Mag. Nat. Hist., ser. 5, 
vol. iii, p. 141, pl. xxi, figs. 1, 2, 8, 
cet. excl. 
1883. Non — —_ Hinde. Cat. Foss. Sponges, p. 152, pl. xxxii, 
figs. 2—2 f. 
The typical example of the species is a club-shaped Sponge, about 165 mm. in 
height by 50 mm. in extreme width. It gradually increases in thickness from its 
base to the rounded summit. The Sponge is broken into several pieces, and its 
form is to such an extent enveloped and concealed by the matrix, that I have not 
attempted to figure its outline. 
The canals which apparently traverse the Sponge longitudinally are sinuous in 
their course, and from *5 to *8 mm. in width. The surface of the Sponge is also 
excavated by numerous ovoid or wedge-shaped pits from 1 to 1°5 mm. in length ; 
some of these extend but a short distance into the Sponge, and exhibit smooth 
sides. They are regarded by Mr. Carter as the burrows of crustaceans. 
The minute stellate and globo-stellate spicules occur in small groups on the 
surface, and in the interior of the Sponge; their rays terminate obtusely. They 
have an average diameter, including the rays, of *3 mm. he rays of the smaller 
hexactinellid spicules, which partly compose the body of the Sponge, are about *3 
mm. in length; whilst in some of the larger spicules, which are only partially shown, 
the rays reach to 2°3 mm. in length by *3 mm. in thickness. The spicules and 
fragments figured on Pl. VIII, figs. 2—2 gq are drawn from the type-specimens 
forwarded to me by Mr. J. Thomson and by Mr. Carter, and they are the most 
perfect which could be found in them. 
Distribution.—Carboniferous : highest beds of Upper Limestone of the South- 
west of Scotland, near Glasgow (J. Thomson). 
Genus.\—SPIRACTINELLA, Hinde, gen. nov. 
Syn.—Holasterella (in, part), Carter, Hinde. 
Form of Sponge unknown, it is composed of simple hexactinellid spicules, and 
forms derived from them, which apparently were quite free from each other, and 
merely held in position by the soft structures of the Sponge. The simple hexac- 
1 Yretpa, anything wound round; dax«riv, ray, dimin. 
