466 DR. J. S. BOWERBANK ON THE SPONGILLID^. [Nov. 24, 



angles to the surface of the ovary, without any arrangement ; but in 

 no case do they appear to be projected in lines radiating from the 

 centre of that organ. 



The only Spongilla with which this species might be confounded 

 is -S. alba, from the tanks of Bombay ; but the oscula are not con- 

 gregated in groups as in that species ; and the spicula of the oraries, 

 although of the same form as those of S. alba, differ from them in 

 being profusely furnished with numerous stout, cylindrical, more or 

 less obtuse spines near the middle of the shaft ; while the spines 

 near the middle of the shaft of those of S. alba are fewer in number, 

 not so strongly produced, and are conical and acutely terminated. 



Spongilla Lordii, Bowerbank, MS. 



Sponge sessile, coating; surface even, smooth. Oscula simple, 

 dispersed. Pores inconspicuous. Dermal membrane pellucid, aspi- 

 culous. Skeleton-spicula acerate. Ovaria congregated on the basal 

 membrane, very numerous ; spicula entirely spined, fusiformi-cylin- 

 drical, dispersed on the surface. Basal membrane abundantly spi- 

 culous ; spicula dispersed, same as those of the ovaries. 

 . ^j Colour ochreous yellow to green. 

 i/^ dn^-^t-*^^^ CU JHab. Lake Osogoos, and other lakes and rivers tributaries to the 

 mii/k^ Columbia River ; on the east slopes of the Cascade Mountains, about 



/"^•H^ 6000 feet above the level of the sea (Mr. J. H. Lord). 



Examined in the dried state. 



The Sponge embraces the stems of a large species of reed for 8 or 

 10 inches of its length, and is about 6 or 9 lines in greatest thick- 

 ness. In its general habit and the structure of its skeleton it closely 

 resembles our British S. Jluviatilis ; but it differs from that species 

 in the mode of disposition and structural peculiarities of the ovaries, 

 which more closely resemble those of our British S. lacustris, from 

 which, however, it differs in having the spicula of the ovaries nearly 

 straight, while those of the last-named species are usually arcuate. 

 The dermal membrane of S, lacustris also abounds in entirely spined 

 tension-spicula, while that of S. Lordii is aspiculous. 



There is a peculiarity in many of the spicula of the ovaria that I 

 have never before seen in those of any other known Spongilla ; and 

 that is, the radiation of secondary canals from the central one of the 

 spiculum to the outer surface. These secondary canals sometimes 

 terminate in spinous projections ; but this is not always the case. 



I observed fragments of similar spicula in the infusorial earth from 

 Duval's Creek, near Lake Munroe, St. John's River, Florida, sent to 

 me by the late Prof. Bailey, of New York. It is therefore probable 

 that S. Lordii will be found in the lakes and rivers of that district as 

 well as at Vancouver's Island. This species is interesting from its 

 close alliance in structure to the European type species of the genus, 

 and from the very slight structural resemblance it has to the nume- 

 rous species of the Amazon River, the principal characters by which 

 it is connected with the latter series of species being the mode of the 

 congregation and disposition on its basal membrane of its very nume- 

 rous ovaries. 



