BRITISH SPONGIADjE. 313 



torted in the course of its growth, and the branches have 

 united where they have touched each other. The warted 

 appearance of the surface is very strongly produced in Mr. 

 Cooper's specimen, but in the other two referred to it is not 

 nearly so apparent, in consequence of the peripheral fasci- 

 culi being so numerous and so close to each other as to 

 almost obscure their fascicular character. Mr. Cooper's 

 specimen has the natural base, which does not spread to a 

 greater extent than about twice the diameter of the prin- 

 cipal stem of the sponge. This species does not appear to 

 attain a great size ; the largest specimen I have seen is 

 four and a half inches high and four inches broad, and the 

 principal stem does not exceed one fifth of an inch in 

 diameter. 



8. Dictyocylindrus virgultosus, Boiverbank. 



Sponge. Sessile, virgultose; branches simple, ascending, 

 very spinous. Oscula simple, dispersed. Pores in- 

 conspicuous. Dermal membrane pellucid, aspiculous. 

 Skeleton : spicula acuate or attenuato-cylindrical, 

 large and long, rarely subclavate. External defensive 

 spicula, primary series, acerate or fusiformi-acuate, 

 short and slender, very numerous, fasciculated, diver- 

 gent. Internal defensive spicula subclavate, attenuato- 

 acuate, entirely spined, variable in size, occasionally 

 very large and long ; spines conical, minute. 



Colour. Dried, dark greenish-gray. 

 Habitat. Shetland, Rev. A. M. Norman. 

 Examined. In the dried state. 



I received nine specimens of this sponge from the Rev. 

 A. M. Norman ; none of them exceeded an inch in height. 

 The body of the sponge is irregularly massive and sessile; 

 at about a quarter of an inch from the base it divides into 

 a number of upright, straight, attenuating branches, which 

 appear never to subdivide or dichotomise. Very few of 



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