316 L. K. CRAWSHAY. 



can hardly be applied to this specimen, it would seem to approximate 

 closely to that species. 



Esperella sp. 



At Position 72, one specimen, forming a thin even investment on one 

 valve of living Peden opercularis. 



Depth, 43 fath. 



I find no described species to which this specimen seems referable. 

 The main lines of the skeleton are composed of smooth styli, decidedly 

 but not strongly clavate ; fairly uniform in size, and averaging about 

 240 fj. by 4 }x. These arise as numerous loose fasciculi, composed of 

 about a dozen spicules, which subdivide and occasionally anastomose in 

 rough curves, and split up internally or at the surface in fan-like 

 extensions. Irregularly disposed styli in the interspaces are not very 

 numerous. The microsclera are of five forms : (1) large palmate 

 anisochelae averaging about 30 jj. in length, arranged mostly in 

 rosettes ; (2) large bidentate anisochelae of same size, often associated 

 in rosettes with the preceding, and possibly an immature form of 

 them ; (3) small bidentate anisochelae, variable in size, but averaging 

 about 12 yu in length, mostly scattered, not very numerous; (4) 

 sigmata, about 30 fj. (one only was observed in a preparation lying 

 in an unsuitable plane for measurement) ; (5) very slender toxa about 

 130 ij. in length. The toxa are chiefly associated with embryos at the 

 base of the sponge, and one pole of one of these embryos is covered 

 with rosettes of the third form of anisochelae as close to one another as 

 they can lie. It is quite possible that this specimen is an irregular 

 form of Bowerbank's Raphiodesma fiorcum. In habit of growth and in 

 most of its characters it strongly resembles his description of that 

 species. The noteworthy differences are that in the latter Bowerbank 

 makes no reference to the small anisochelae as tension spicula, but 

 refers to numerous small sigmata in their place which do not seem to 

 occur at all in this specimen. That he should make no mention 

 of toxa is perhaps not surprising, since they scarcely seem to exist in 

 the specimen apart from the embryos, whatever their function in this 

 respect may be. Very fine styli of about 140 fx in length are likewise 

 associated with these embryos, and almost exclusively so. 



Desmacidon fruticosus (Montagu). 



At Position 7, one, on valve of Pectunculus glycimeris. Small sigmata 

 very numerous. 

 „ „ one large specimen. Small sigmata scarce. 



„ 58, two detached specimens ; the largest 70 mm. in 

 height. Sigmata and chelae very scarce. 



