322 Mr. H. J. Carter on the 



might be stated that, while attached to the survey of the 

 south-east coast of Arabia in 1844-46, I made a collection of 

 all the marine sponges that I could find there, and sent them 

 home just afterwards to Dr. Bowerbank, who received and 

 thanked me for them ; but here this matter ended, and would 

 have ever done so had I not felt the loss of a report on them, 

 and especially the specimens themselves, in an-anging the coi- 

 tion of the British Museum, where I should have been most 

 glad of representations of this part of the world. 



If another survey is made of that unfrequented shore, and 

 another collection of sponges is gathered from it, I trust that 

 the latter may not be attended by such misfortune ! 



Two or three of these sponges, however, whose figures I 

 had drawn and whose duplicates I had retained, I have been 

 able to describe and illustrate (' Annals,' 1869) ; and since 

 then my kind friend Dr. J. E. Gray has, by his desire that 

 I should go on with the study of the marine sponges gene- 

 rally, and his unceasing exertions to place within my reach 

 every thing in his power to facilitate this inquiry, ending with 

 opportunities for examining and arranging the whole collec- 

 tion in the British Museum, caused me to obtain such a prac- 

 tical knowledge of the subject, so far as specimens of sponges, 

 both dry and in spirit are concerned, that I felt it absolutely 

 necessary to preface a resume of all this by that physiological 

 study of the development of the living marine ones which my 

 present residence on the sea-shore enables me to follow. 



For this purpose I have for some time past been desirous of 

 finding out specimens of these sponges in an oviparous state ; 

 and although this may be often done in any part of the year 

 while the ovum is very young, or only just distinguishable, 

 yet it has not been until lately that I have found specimens of 

 these sponges in which the ovum has become much enlarged 

 and developed into the embryonal state — that is, ready for deli- 

 very. 



Of the calcareous sponges it was stated ('Annals,' 1874, 

 vol. xiv. pp. 98 & 107) that Grantia compressa &c. went 

 through this oviparous development in the months of March, 

 April, and May, and that at this time none of the siliceous 

 sponges that I could find appeared to be in a like condition. 



Since then, however, viz. on the 30th July and 29th Au- 

 gust respectively, I have found several siliceous sponges, 

 together with one of the non-spiculous ones belonging to 

 Schmidt's Halisarcin^e, viz. Halisay'ca lohularis^ Sdt., in which 

 the ovum has presented all the stages of development, from its 

 earliest appearance to the full-formed embryo ; that is to say. 



