[lamrk] sponges from THE ATLANTIC COAST OF CANADA 197 



The suri'acc ol' (lie main })art of the sponge is densely hispid owing to the 

 presence of long projecting tylostyli. 



A large, stout, oscular tuhe, situated in (he midst of the fistular 

 processes, is present in each of the specimens. In the most perfect speci- 

 men (Plate III., fig. 1) the tube is 15 mm. high, 7 mm. broad at the base 

 and tapering gradually to the distal end terminates in an oscular open- 

 ing 3-5 mm. broad (see o^ in figure). This specimen is 42 mm. long, 

 26 mm. broad with thirty-five fiistulœ about 14 mm. in average length. 

 Another specimen from the same locality has fistulas about 16 mm. in 

 length, but the oscular tube is short and broad in proportion to its height ; 

 the tube is 7'5 mm. high and 45 mm. broad. One other specimen from 

 a different locality has thirty fistula? whose maximum length and breadth 

 are 11 and 2-5 mm. respectively. Its oscular tube is of the same length 

 as the fistula?, but is proportionately stouter. 



The measurements of the spicules are : 



1. Cortical tylostyli — (rt) from the dermal layer of tlie cortex ; length 

 from 0137 to 0287 mm., thickness from 0-013 to 0-020 mm. (Plate III, 

 fig. la) ; (6) from the inner layer of the cortex; length from 0-479 to 

 0-753 mm., average thickness 0-013 mm. (Plate III., fig. lb). > 



2. Tylostyli from the main fibres ; average length 1-5 inm., average 

 thickness 0-027 mm. (Plate III., fig. Ic). 



3. Projecting tylostyli ; maximum length 5-18 mm., thickness show- 

 ing a variation of from 0-013 to 0-027 mm. (Plate III., tig. Id). 



Localities. — Twelve miles northwest of Bear Head, Anticosti, in 120 

 fathoms, mud, temperature of mud 38° Fahr., one specimen preserved in 

 alcohol, J. F. Whiteaves, 1871. Fifteen miles from Cap des Rosiers, in 

 160-170 fathoms, mud and stones, tempei-ature of mud 38° Fahr., two 

 specimens preserved in alcohol, J. F. Whiteaves, 1872. Eighteen miles 

 southwest by south of Southwest Point, Anticosti, in 210 fathoms, one 

 young specimen, in alcohol, J. b\ Whiteaves. 



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

 coast of United States (Verriil) ; south of Nova Scotia (Challenger). 



Foreign distribution. — Coast of Devon and northeast coast of Ireland 

 (Johnston) ; Larne Lough, Ireland, Guernsey, Shetland and Orkney 

 Islands (Bowerbank) ; lat. 75° 20'5 N., long. 46° 40' E., lat. 71° 18' N"., 

 long. 42° 41' E., lat. 77° 7' N., long. 49° 37'5 E., and lat. 72° 29' N., long. 

 25° 48' E. (Vosmaer). 



Trichostemma hemisph.ericum, M. Sars. 



(Plate II., fig. 7, 7a— e.) 



Trichostemma hemisphœricum, M. Sars. In G. O. Sars's paper on Some Remarkable 



Forms [of Animal Life from the great deeps 

 off the Norwegian coast, p. 62, pi. vi., figs. 1-15. 

 1^72. 



Sec. IV., 1896. 12. 



