298 Rev. A. M. Norman on a new Hebridean Sponge. 



H. Pattersoniij Bow. Off Loch Ewe, in company with Antedon 

 celticuSj Holothuria intestinalis, Poromya granidata, and 

 other interesting animals, in some abundance. Colour a 

 very dark brown. 



" Halichondria expansa, Bowerbank, n. sp. 



" Sponge compressed, expanding laterally, parasitical. Sur- 

 face smooth and even. Oscula simple, minute, dispersed. Pores 

 inconspicuous. Dermis furnished with a stout irregular net- 

 work ; rete composed of broad flat polyspiculous fasciculi ; 

 sjncula fusiformi-cylindrical, terminations incipiently spinous, 

 spines very minute ; tension-spicula acerate, long, and slender, 

 frequently flexuous, basal terminations incipiently spinous, 

 few in number ; retentive spicula bidentate, inequianchorate, 

 minute, and few in number. Skeleton rather compact ; rete 

 variable, containing from one or two to five or six spicula ; 

 spicula fusiformi-acerate, rather stout, incipiently entirely 

 spinous, base prominently spinous. Interstitial membranes 

 pellucid ; tension and retentive spicula the same as those of the 

 dermal membrane, few in number. Gemmules membranous, 

 aspiculous. 



" Colour in the dried state dark brown. 



"Hab. Skye (Eev. A. M. Norman). 



" Examined in the dried state." 



The type specimen is attached to the hydrocaulus of Dipha- 

 sia pinaster, dredged in the Sound of Skye, in the form of two 

 triangular expansions, each about three-quarters of an inch in 

 the greatest diameter. 



Isodictya cinerea (Grant). This is another species which seems 

 to vary greatly in colour. The Tobermory examples were 

 brown. 



/. infundibidiformis (Johnston). In deep water, the Minch. 



/. laciniosa, Bowerbank, n. sp. [vide Norman, Shetland Dredg- 

 ing Report, Brit. Assoc. Report, 1868 (1869)]. The 

 Shetland type on which this species is established is one 

 of the largest and, at the same time, one of the most ele- 

 gant of British Porifera. A small water-worn fragment 

 procured in the Minch gives proof of the existence of the 

 species among the Hebrides. 



Order Keratosa. 



Chalina seriata (Grant) . Tidemarks, Tobermory, on the under- 

 side of larae stones. 



