1908.] ON CAPE VERDE ISLANDS SPONGES. 757 



9. On Collections of the Cape Verde Islands Fauna made by 

 Cyril Crossland, M.A. (Cantab.), B.Sc. (Lond.), F.Z.S., 

 (late o£ the Gatty Marine Laboratory, St. Andrews 

 University), from July to September 1904. — The Cal- 

 careous Sponges. By A. G. Thacker, A.R.C.S. (Lond.), 

 Research Scholar in Zoology at the Royal College of 

 Science *. 



[Received June 15, 1908.] 

 (Plate XL. t and Text-figures 155-166.) 



It is somewhat remarkable that, although a considerable 

 number of Calcareous Sponges has been described' from the 

 Azores and from the Canary Islands, only one species, Grantia 

 tuherosa, dredged ofi" St. Vincent by the ' Challenger,' has been 

 hitherto recorded from the Cape Verde Islands. It was therefore 

 to be expected that the dredging operations which were carried 

 out by Mr. Crossland, with the aid of a grant from the Carnegie 

 Trustees, in the summer of 1904, would yield some interesting 

 results ; and such has in fact been the case, for of the twelve 

 species contained in the present collection, six are altogether new 

 to science, and several of the remainder are of interest either from 

 the zoogeographical or systematic point of view. 



The twelve species are as follows : — 



Leucosolenia panis (Haeckel). 



Leucosolenia atlantica, sp. n. 



Leucosolenia canariensis (Miklucho-Maclay). 



Sycon quadrangulatum (Schmidt). 



Sycon caminatum, sp. n. 



Grantia intermedia^ sp. n. 



Leitcandra verdensis, sp. n. 



Leucandra rudifera (Polejaeff). 



Leucandra sericata (Ridley). 



Leucandra typica (Polejaeff). 



Leucandra crosslandi, sp. n. 



Leucandra gemmipara, sp. n. 



Perhaps the most interesting of these species is the remarkable 

 sponge, Leucandra rudifera, of which only a few fragments have 

 been previously found and which is characterised by the possession 

 of some curious and unique spicules in its gastral cortex. 



Another fact, which is of some systematic interest and to which 

 I wotdd call attention, is the compi-ehensive sense in which I have 

 been obliged to use the name Leucosolenia canariensis. From the 

 great variability of certain characters in some of the Ascons in 

 this collection, it seems probable that the characters by which 

 certain sponges (notably Leiocosolenia nanseni Breitfuss, and 



* Communicated bj^ Professor Aethue Dendt, D.Sc, F.R.S., F.Z.S., SecL.S. 

 t For explanation of the Plate see p. 782. 



