BY R. VON LENDENFELP, PH.D. 309 



we lind in most of the places where two fibres join, large granules 

 of sand which exceed in diameter the fibres 5 — 15 fold. These 

 grains are clothed with a fine coating of spongiolin and form an 

 integral part of the whole skeletal system. (Plate XXXIII.) 



The lacunes between the membranes are connected with one 

 another, and the outer world by numerous large round pores. 

 The distal portions of the true sponge-body extend in the shape of 

 conuli in a radial direction some distance beyond the lacunose 

 tissue. Inhalent pores and oscula occur throughout the whole of 

 the surface of the true sponge-body. Some of these — on the pro- 

 jecting conuli — open direct into the outer water. Most of them, 

 however, open into the system of lacunae. The inhalent pores are 

 covered with a sieve membrane, they lead into low, tangentally 

 expanded subdermal cavities. The inhalent canals which originate 

 from this subdermal cavity are not very large, much curved and 

 only very slightly branched. The ciliated chambers appear 

 spherical, and are ^ — ^ as large as the canals, having a diameter 

 of 0-04 mm. They open with a large circular Chamber Osculum 

 dii'ect, without special canal into the large exhalent canals which 

 unite to form extensive oscular tubes. The oscula are numerous 

 and scattered irregularly over the surface of the sponge. Nai'dorus 

 and Auloplegma forms. 



64 SPECIES. 



AULENA VILLOSA. NOVA SPECIES. 



(Plates XXX., XXXIV. 



At present the only species of the genus. 



Shape. 



This sponge is comparatively rare. The specimens which I 

 have seen were bulbous without exception ; spherical or oval. 

 The sponge is attached to suitable surfaces in the sea by a very 

 small portion of the surface but not pedunculate. It resembles in 

 this respect the massive forms of Chondrosia. The sponge appears 

 to a certain extent radially symmetrical round a vertical axis. 



