198 ROYAL SOCIETY OF CANADA 



Trichosteinvia hemisphœricum, Whiteaves. 1874. Report on deepsea dredging 



operations in the Gulf of St. Lawrence, p. 9 and 

 Am. Jour. Soi. and Arts, vol. vii., p. 2. 

 Polymastia heinisphcerica, y osmatn: LSSii. The sponges of the " Willem Barents" 



Expedition 1880 and 1881, p. 12, pi. 1., figs. 4, 20, 21. pi. 

 ii., figs. 17-20, pi. iii., flgs. 1-5 and pi. v., figs. 8-16. 



There are thi'ee specimens of this sponge from the (rulf of St. Law- 

 rence. The Uirgest specimen is 64 mm. long, 37 mm. broad, with a thick- 

 ness of about 17 mm. Near the basal edge the belt formed by the pro- 

 jecting spicules is about 6 mm. broad. There is no cortex on the basal 

 surface which presents the appearance of having l)een attached to a 

 stone. The upper surface bears about sixty pa])illa% the largest of which 

 do not exceed 3 mm. in height and have a maximum basal diameter of 

 6 mm. There appears to be a minute oscuium at the summits of some of 

 the papilhe. 



Spicules taken from the largest specimen gave the following measure- 

 ments : 



Tylostyli from the fibres uf the interior ; length varying from 0'3G9 to 

 0-876 mm., thickness from 0016 to 0010 mm. (Plate II., tig. la). 



Cortical tylostyli ; from 0-089 to 0-16!» mm. long and from 0-002 to 

 0-006 mm. thick. (Plate II., tigs. 76, 7c, 7^/). 



Projecting tylostyli fro^n basal edge ; maximum size 2-5 by 0-02 mm. 

 (Plate II., fig. le). 



Of the other two specimens, one is similar in form to the above but 

 smaller, whilst the remaining one is considerabl}^ smaller but is higher in 

 proportion to its breadth. The small specimen bears papillae which 

 occasionally reach a height of 5'5 mm. 



Locality. — Between Anticosti and the north shore of the Gulf of 

 St. Lawrence, eight miles distant from Charleton Point, Anticosti, in 112 

 fathoms, large and small stones, three specimens, in alcohol, J. F. 

 Whiteaves, 1871. 



Distribution. — Gulf of St. Lawrence (.T. F, Whiteaves) ; northeast 

 coast of United States (Verrill). 



Foreign distribution.— Ijoi'oten, Norway (Sars) ; Arctic Ocean, off 

 the coast of Norway (Vosmaer). 



Tentofuum SEMisUBERiTEs, Schmidt sp. 



(Plate III,, tigs. 2, 2a— c.) 



Thecophora .Heniisuberites. Schmidt. 1870. Spong. Atlant. Gebiet., p. 50, pi. vi., 



fig. 2. 

 Thecophora Ibla, Wyville Thompson. 1878. The Depths of the Sea p. 148, fig. 24. 

 Thecophora semisuberites, Whiteaves. 18^4. Report on deep-sea dredging oper- 

 ations in the Gulf of St. Lawrence, p. 9. 

 Thecophora ibla, Verrill. 1874. Am. Jour. Soi. and Arts, vol. vii., p. 500, pi. viii.. 



