3 



The spongilla is sessile, and branches much, woll-growu speci- 

 mens much resembling fully developed examples of \s h(ci(.sfris. 



Len-th of skeleton-spicula 0.018. Dermal and interstitial 

 spicula, 0.0015 to 0.0017 inch. 



Fig. 3.— a, ordinary skcletou-spiculum. A. and B., ordinary 

 capsular and dermal spicula. 



.SpongUh, stagu„/;s, sp. nov. Sponge (jncrustin-, forming 

 patches several inches in diameter, and from half an inch to an 

 inch thick; greenish; lobular, somewhat hispid. Oscula simple 

 key-hole shaped, or double; large, 0.25 tu 0.50 in. Scattered,' 

 ,sub-crateriform. Skeleton-spicula acerate and fusiformi-acerate, 

 .-lightly arcuate, 0.011 to 0.018 in. Ion- Most of the stouter 

 spicula medially spined, the apices always naked ; spines small, 

 sparsely distributed. Qvaria, sub,globose, diameter, 0.025 in.' 

 Rotuku, about equal in size, flat, very deeply and irre-ularly 

 dentate, diameter about equal to length of shaft of spiculum, or 

 0.0005 in. ; the rays not acute. Shaft, thick, cylindrical, -ener- 

 ally with a boss at each (md. 



//ih. North-west Angle Inlet. Lake of the Woods; River St. 

 Lawrence near Montreal. 



The two forms ,. skeleton spicula seem to pa.s into each 

 other, and in specimens from both localities, are \ cry irre-ulir 

 in size. The birotulate spieula-especialiy in the L-jke of the 

 Woods speeimens-are very apt to be dei;)rnu:d. A number of 

 siMall, entirely sp.ned, straight. .,btu,s. spicula, about one-third 

 the length ..f the skeleton-spicula, were ibund with the others- 

 alter treatment with acid. They were searched for in all parts 

 of the sponge, but finally found enclosed in some of the gem 

 mules, and apparently in connection with the young spon-e." 



This species, which is nearest the European type A', f/oriatf/h 

 ot eJohnstou, was found in great abundance at the first'mentioned 

 locality, in July, 1878. It was growing on floating lo-s and 

 branches, and many specimens were filled with large -emmules 

 It is probably the species the existence of which was'suspected 

 by Pr. Bowerbank, who says, in the conclusion of his notice of 

 >V. /)a>r,onl .•— " In (he preparation of these .spicula for examina- 

 tion I found a few birotulate ones, having the rotulse very 

 deeply divided. These spicula were no part of the spon-^e in 

 course ot description, but were undoubtedly from the gemmules 

 of another species inhabiting the St. Lawrence." 



