PORIFERA OF THE L.M.B.C. DISTRICT. 221 



dredged on the " Hyaena" expedition of May 25th, 1890, 

 in Penrhos Bay (10 fathoms), and off Khoscolyn Beacon 

 (12 fathoms), on the west coast of Anglesey. The cortex 

 of the hving sponge was cadmium-yellow, its inner portion 

 brown. The diameter of the specimens is 1*5 to 2 cm. 

 One of them was covered with about thirty buds.* 



One specimen of this species had previously been dredged 

 in Church Bay, Holyhead. 

 Dercitus hucJdandi, Bowerbank. 



This sponge, which had already been recorded by Mr. 

 Higgin under the name Dercitus niger, C, from Holyhead, 

 has now also been discovered at Puffin Island. I found a 

 few specimens of it at the entrance of the large cave on the 

 north end of the island, at low spring tide, April, 1889. The 

 largest of the specimens measures 3 cm. by 2 cm. in hori- 

 zontal direction and 0"6 cm. in height. Colour, dark black. 



For an extensive list of the literature, and a revised 

 description of this species, see Sollas.f 

 Seiriola compacta, Hanitsch (PI. XIII., figs. 1 — 4). 



In my former report on the Porifera of the L.M.B.C. 

 District I I described and figured a new species of a tetrac- 

 tinellid sponge under the above name, which I took to be 

 the representative of a new family. But in doing so I fell 

 into a serious error, and I have to thank Professor SoUas, 

 D.Sc, for pointing out the mistake to me. The two layers 

 which I described as ectosome and choanosome of one 

 sponge are really two quite separate sponges, an encrust- 

 ing Suberite and an encrusted Stellettid. " Each is," as 

 Prof. Sollas writes me, after having seen my preparations, 

 " a separate individual, the Suberite is defined from the 



* Compare Bowerbank, " British Spongiadse," vol. ii. p. 94. 

 + Sollas, " Report on the Tetractinellida collected by H.M.S. ' Challenger,'" 

 p. 108. 



X Proc. Liverpool Biological Society, vol. iii., p. 169 — 172, pi. vii. 



