240 A MONOGRAPH OF THE 



erosa, represented in his Sponge Tables XLT, is undoubtedly 

 the same species as that designated Sponffia coalita by Dr. 

 Grant, and Halichondria coalita by Johnston. 



8. Halichondria djstorta, Bowerhank. 



Sponge. Branching, branches compressed, terminations 

 hemispherical. Parasitic. Surface smooth. Oscula 

 simple, small, numerous, dispersed. Pores incon- 

 spicuous, numerous. Dermal membrane pellucid, 

 abundantlyspiculous, reticular; spicula acerate, slender, 

 rather short. Skeleton spicula acerate and acuate, 

 stout, variable in proportions ; interstitial membranes, 

 tension spicula, acuate and acerate, long, straight, 

 and somewhat slender. 



f7o/oMr.— When dried, light gray. 



Habitat.— ^&&r Torbay, Mrs. Griffith. River OrweU, 

 Dr. W. B. Clarke. 



Examined. — In the dried state. 



I have seen but two specimens of this sponge ; the first 

 was procured by Mrs. Griffith from one of the Brixhara 

 trawlers the exact locality cannot, therefore, be given ; the 

 second one was presented to me by Dr. W. B. Clarke, of 

 Ipswich, who dredged it in the River Orwell. Mrs. 

 Griffith's sponge consists of a fan-shaped series of short 

 distorted compressed branches which occasionally anasto- 

 mose, and are nearly all in the same plane. The basal 

 portion of the branches are solid and cork-like in 

 texture; the denseness decreases gradually in proportion 

 as we approach the termination of the axis where it is 

 scarcely perceptible. This character does not exist to so 

 great a degree in Dr. Clarke's specimen. The height of 

 the first specimen is six inches, and its greatest width 

 seven inches. Dr. Clarke's sponge is about the same 

 heio-ht, but not so broad ; in other respects it is very similar 



