152 ]\Iessr.5. A. Dendy and S. O. Ridley on 



XVII. — On Proteleia * Sollasi, a neio Genus and Species of 

 Monaxonid Sponges allied to Polymastia. By ARTHUR 

 Dendy, B.Sc, Associate of the Owens College, and 

 Stuart O. Ridley, M.A,, F.L.S., of the Zoological 

 Department, British Museum. 



[Published by permission of the Lords Commissiouers of the Trea.'^ury.] 



[Plate v.] 



Amongst the many new and interesting Monaxonid sponges 

 obtained by the ' Challenger ' there is one which, while closely 

 agreeing in most respects with the Suberitid genus Polymastia^ 

 is distinctly marked off from all species of that genus by the 

 possession of a very remarkable spicule, which, both in form 

 and position, strongly calls to mind the characteristic "grapnel" 

 of the Tetractinellicla. 



Through the kindness of Mr. Murray, Director of the 

 ' Challenger ' Commission, we have been enabled to publish 

 in this place a short account of this interesting sponge, whose 

 well-marked characters entitle it to form the type of a new 

 genus. As the chief points of interest concern its spiculation 

 and its relation to other forms as thereby indicated, we shall 

 not attempt here any histological description of the soft parts, 

 reserving any remarks which may be required on that head 

 for our forthcoming Report on the ' Challenger ' Monaxonida. 



Although it is always more or less hazardous to base a 

 generic diagnosis on a single species, yet the convenience of 

 such a diagnosis is so great that it is preferable to give one, 

 on the understanding that it may be subject to alteration when 

 more species are discovered. 



Genus Peoteleia. 



Sponge sessile, corticate; upper surface covered with 

 mammiform processes ; skeleton-spicules spinulate and (or) 

 acuate, and also a spicule with a grapnel-like apex projecting 

 freely beyond the surface of the sponge. No flesh- spicules. 



The genus undoubtedly belongs to the family Suberitidse. 



• TTporeXfia, a beginniuo- ; so called because it possesses the rudiment 

 of a gi'apnel-spicule. 



