104 BIOLOGICAL. SURVEY OF 



loPHON Gray 

 loPHON CHELiFER Ridley and Dendy 



Ridley and Dendy (1887, p. 119, pi. 16, fig. 3; pi. 17, figs. 

 1, 3, 8). Lambe (1894, p. 30, pi. 2, figs. 7, 7a-f ). 



This species is very abundant in this region and is found 

 always encrusting on Terebratulina septentrionalis. The 

 older sponges are massive and lobate. In the living condition 

 they are brownish-gray, but soon become dark brown or black 

 in alcohol. 



Skeleton. This is composed of an irregular loose reticula- 

 tion of spined spicules with a more or less rectangular mesh- 

 work. Two main lines of spicules are roughly distinguish- 

 able ; one of these is approximately perpendicular to the sur- 

 face of the sponge. 



Spicules. Megascleres consist of spined styli and tylota. 

 1) The spined styli compose the major portion of the skeleton 

 and vary from .161 mm. to .243 mm. in length. 2) Tylota 

 with minutely spined ends are found in the dermal membrane 

 and are few in number when compared with the abundance 

 of spined styli. The tylota vary from .162 mm. to .243 mm. 

 in length. 



Microscleres consist of anisochelae and bipocilli. 1) The 

 anisochelae vary from .015 mm. to .019 mm. in length. 2) Bi- 

 pocilli, having the characteristic pronged ends, measure .009 

 mm. in length. These bipocilli are more regular and con- 

 sistent in shape than those figured by Ridley and Dendy for 

 specimens from the south Indian Ocean and agree well mth 

 those figured by Lambe for this species from the Straits of 

 Georgia (Vancouver Island). Lambe states that the speci- 

 mens from the (julf of St. Lawrence are exactly similar in 

 spiculation to those from the Pacific coast. 



Geographical distribution. Gulf of St. Lawrence (Lambe), 

 Mount Desert Region. 



MicROCiONA Bowerbank 

 MicROCiONA PROLiFERA Verrill 



George and Wilson (1919, p. 157, pi. 62, fig. 31; pi. 63, figs. 

 35, 36; pi. 66, fig. 57a-e). 



