456 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



radial to the surface, in the peripheral part of the sponge and seem 

 to be especially abundant at the apices of the rounded protuberances. 



In Dendy's type no microxeas are mentioned. The microrhabds 

 are described as " usually fusiform and strongylate, with very min- 

 utely roughened surface "; 16 u. long. In the Albatross specimen the 

 microrhabds are similar, the ends strongylate to oxeate but never 

 sharp; 12-18 \l long by 2-3 [x thick at the middle. They form a 

 thin layer, one spicule thick, external to the triaene cladomes; are 

 especially abundant round the pores, and common in the walls of 

 the canals and throughout the interior. 



Using Lendenf eld's definitions of Theonellid genera (1903), the 

 sponge falls in Kaliapsis. But the spinose character of the outer 

 face of the disk in the triaene, on which Lendenfeld lays emphasis, 

 does not seem to be a sufficient reason for separating such species 

 from Discodermia. 



DISCODERMIA EMARGINATA Dendy. var. LAMELLARIS, new variety. 



Plate 43, fig 5. 



Under this heading I record two specimens from station D5482 

 of lamellate habitus, one face bearing the oscula, the other the 

 pores, as in some other species of the genus (D. discifurca Sollas, 

 D. ornata Sollas). The skeletal and other differences from the type 

 are slight, and it is not improbable that the variety merely repre- 

 sents an older stage of growth, the type a younger one. 



In the specimen illustrated the base is amorphous, from which the 

 body rises in the shape of an irregular lamella about 5 mm. thick. 

 This is curved, showing a concave and a convex surface. The con- 

 cave surface bears the oscula which are just visible to the eye; the op- 

 posite surface bears the pores. The greatest diameter of the whole 

 mass is 50 mm. 



In the other specimen, the body rises from a flattened base as a 

 curved lamella similar to the preceding. But several lamellate out- 

 growths seem here to have fused with one another in an irregular 

 way, so as to surround and imperfectly roof in a space. Greatest 

 diameter of the whole mass 65 mm. 



The oscula are abundant, 250 \x. to 1 mm. apart. Most are closed 

 by the usual thin membranes, but the cylindrical oscular canals lead- 

 ing radially inward are conspicuous. The osculum, when fully open, 

 probably has about the diameter of the oscular canal, which ranges 

 from 80 to 1S5 \i, exceptionally reaching 250 a. 



The arrangement of pores is interesting. They are much more 

 numerous than in the specimen assigned to the type, but of about 

 the same size. They are closely set in rows, one pore wide. The rows 

 of pores interconnect with one another and thus give rise to an ir- 



