194 ROYAL SOCIETY OF CANADA 



same species. The other specimen is growing on the inside of a valve 

 of a specimen of Cyprina Islandica, L. 



The spicules of the Sable Island specimens are of the following- 

 sizes : — Megasclera ; tylostyli varying in length from O'lGS to 0-406 

 mm. and in thickness from 0-008 to 0003 mm. (Plate II., hg. 4(/). 

 Microsclera ; the '• intlato-cvlindricar' s])icules of Bowerbank ; from 

 0-019 to 0-03n mm. long, with a maximum thickness of O'OOS mm. (Plate 

 II., tigs. 46, 4r). 



Locality. — Sable Island, two specimens, dry, Sir William Dawson. 



Foreign distribution. — Coasts of (Ireat Britain (.lohnston and Bower- 

 bank). 



SuBERiTES HiSPiDUS, Boworbauk. 



(Plate II., tigs. 5, 5a, 5b. 5c. M.) 



Tefhea hispida, Bowerbank. 1864. Canadian Naturalist, second series, vol. i., p. ;^04. 

 Tcthea hispida, Verrill. 1874. Am. .Jour. Sci. and Arts, vol. ill., p. 40. 



This sponge was tirst descriljed by Bowerbank from a specimen 

 dredged by Sir "William Dawson, at Portland, Maine. The author of the 

 species received a small slice of the specimen when dry, but from the 

 smallness of the piece was not able fully to make out some of the salient 

 characters of the sponge. In the original descri^Jtion no measurements 

 of the spicules are given. 



Later a single specimen was dredged by Mr. Whiteaves, in the Clulf 

 of St. Lawrence, who at the time recognized its indentity with the type 

 of the species. 



The sponge is sessile, subhemispherical with a moderately convex 

 u])per surface ; found growing on rocks. The type specimen, which was 

 found growing partly on a specimen (jf Balanus porcatus, Da Costa, and 

 partly on the rock to which the barnacle was attached, has a maxi- 

 mum breadth of 37 mm. and a height at the centre of about 12 mm. 

 Mr. Whiteaves's specimen was evidently attached to a stone from which 

 it was separated by the dredge ; it measures 33 mm. across and is 15 mm. 

 high. Colour in spirit, a dull yellowish-gray. Texture firm, compact. 

 Surface even, very hispid. Osculuîn,'à depressed opening, al)Out (> mm. in 

 diameter, situated at the centre of the summit. In the type specimen 

 the depression of the oscular opening below the general surface, is not 

 apparent, owing to the shrinkage of the sponge due to drying. 



Skeleton. — Loose fibres, about 0'137 mm. thick, composed of tylosty- 

 lote spicules, pass from the base of the sponge to the surface. The 

 spicules of the fibres divei-ge slightly on approaching the surface. A 

 cortex about 0-411 mm. thick and made up of two sizes of tylostyli is pre- 

 sent in the upper portion but is entirely absent at the base. The smaller 

 tylostyli, radiating outward, are densely packed together and project 



