REPORT ON THE HEXACTINELLIDA. 129 



smooth, or at most somewhat rough towards the pointed ends, while tlie delicate, freely 

 projecting, fir-tree-like distal, which is two or three times longer, is beset with oblique 

 outwardly directed prongs, and runs gradually to a point towards the outer extremity 

 (PL XXVI. fig. 9). 



The specific name I have given is in honour of my friend and former colleague in 

 Graz, Professor Gurlitt. 



Family III. R os s ell id .^i (Pis. LIII.-LXIX.; PL GIL). 



Goblet- or beaker-shaped, with walls of varying thickness. Some rest either directly, 

 or by means of a longer or shorter cylindrical stalk, upon a solid basis, others are rooted 

 in mud by means of a basal mass of spicules. The external surface of the body is in 

 some smooth and naked, in others armed with prominent pleuralia of varying length. 

 The simple wide gastral cavity opens by a simple, round, more or less broad, oscular 

 aperture, the margin of which is either naked or armed with a border or circlet of spicules. 

 A special characteristic of the family is to be found in the fact that the distal ray of the 

 dermalia is ahoays absent. The dermalia occur as pentacts, tetracts, diacts, or even 

 monacts. The gastralia have usually no freely projecting proximal ray, but in some cases 

 they occur as fully developed hexacts. 



Genus 1. Lanugindla, 0. Schmidt (PL LIII. figs. 3-5). 



1869. 0. Schmidt, Mittheil. dos naturw. Vereines fiir Steiermark, jjp. 89, 2G1. 



1870. O. Schmidt, GrundziigB einer Spongieufauna des atlant. Gebietes, p. 13. 

 1870. Sav. Kent, Montlily Micr. Journ., voL iv. p. 247. 



On a specimen of AphrocalUstes from St. lago, one of the Cape Verde Islands, Oscar 

 Schmidt found in 1870 some small spherical or ellij^soidal sponges of very elastic consist- 

 ence, exhil)iting a central cavity and a wide superior osculum. The outer surface, apart 

 from spicules projecting here and there, was smooth— just as if varnished. The interior 

 contained, according to 0. Schmidt, prominent, smooth or finely spiuose hexacts and simple 

 oxy diacts with intersecting axial canals. In the outer layers, between the projecting 

 needles, hexasters occurred in which each of the short principal rays was soon divided 

 into four or five tuberculated branches, with transverse terminal plates. In the external 

 dermal layer, and at the margin of the osculum, numerous sexradiate spicules occur, 

 besides quadriradiate forms filling up the interspaces, and in part provided with sharply 

 cornered knotted extremities. The smoothness of the outer surface seemed to be due 

 to these four-rayed sjaicules. 



Oscar Schmidt named the newly discovered Hexactinellid Lanuginella, because it 



(ZOOL. CHALL. EXP. PART LIII. — 1880.) Ogg 17 



