164 Dr. J. E. Gray on the Arrangement 



(15) I. jugosa, {20) I. robusta, (25) I. palmata, {SI) I. Nor- 

 mani, (^2) I. jfucorum, {33) I. Alder i, {34) I. Edwardti, (35)7. 

 lohata, (36) I.paupera, (38) /. Clarkei, (39) /. gracilis^ (41) /. 

 Beanii, (42) /. lurida^ (43) /. fimhriata^ belong to Esperiadae. 



With such a mixture in each of the genera, one is not 

 astonished to hear, as one often does, that it is utterly impos- 

 sible to make out any sponge by Dr. Bowerbank's work. Be- 

 lieving that the work contains much that is valuable, I have 

 done what I could, in the paper published in the Proceedings of 

 the Zoological Society, to make it useful to the British zoo- 

 logist, among other ways by referring to the plates in which 

 the spicules of his species are figured. 



Dr. Bowerbank prides himself on having proved that eleven 

 of the fifty-six species of British Sponges described by Dr. 

 Johnston " are only repetitions with new names, or otherwise 

 no species " (Brit. Sponges, i. p. 2). Fui-ther on, at p. 222, he 

 shows his reasons for these reductions. It remains to be seen 

 how many of the 193 British species described by Dr. Bower- 

 bank will suffer the same fate at the hands of his successors in 

 the study of this group of animals. 



It would be very prematm-e, with the very imperfect know- 

 ledge we possess, to attempt to give any arrangement showing 

 the relations that the genera have to each other, though one 

 cannot study them without observing that no linear arrange- 

 ment that can be formed will show more than a few of such 

 relations, and must separate some genera which appear to have 

 considerable analogy, if not affinity, to each other. 



The Coral Sponges {GoralUospongice) ^ for example, are 

 closely allied to the Euplectelladoe^ the genus Aphrocallistes 

 forming a passage between Dactylocalyx and Euplectella. 

 The Coral Sponges and the Euj)lectelladce are joeculiar among 

 Sponges for having the sarcode studded with long-rayed stel- 

 late spicules. And it would not be difficult to point out a num- 

 ber of such alliances ; but this must be deferred until we have 

 more works like the ' British Sponges ' and the ' Sponges of the 

 Adriatic Sea.' I am very glad to hear that Dr. Oscar Schmidt 

 is now engaged on the Sponges of the Mediterranean, and 

 especially of Algeria, and hope he may hereafter be induced 

 to take up the exotic fibrous Sponges. 



It has occm-red to me that if I abstained from dividing the 

 Sponges into Netted and Spicular Sponges in my arrange- 

 ment, and commenced by separating them according to the 

 spicules, as I had divided the Spicular Sponges, the arrange- 

 ment of the families would be simplified and more natural, as 



