SPONGIIDA. 629 



55. Leucortis anguinea *. 

 (Plate LIII. fig. L ; Plate LIV. figs, d, d'.) 



Erect, branched; stem and branches cylindrical, tubular. (Vent 

 opening probably at end of tubo and nearly as wide as tube.) 

 Branches given off at angle of about II" with each other. Wall 

 •25 to -35 millim. thick ; lumen of tube -8 to 1-2 millim. in diameter. 

 Outer and inner surfaces even, smooth. Consistence in spirit elastic, 

 compressible (colour probably whito or grey naturally, at present 

 pale purple, probably derived from other sponges). Skeleton mainly 

 composed of triradiate spicules; those (1) of outer surface sagittal, 

 with large facial angle, viz. 150° to 170°, the distal three fourths of 

 the lateral rays being, in the latter case, bent back so as to be 

 nearly in a line with each other ; basal ray about -2S millim. long, 

 laterals -16 to -22, diameter of rays at base *013 to -019 millim. 

 Surface triradiates occasionally provided with a short stout apical 

 ray. (2) Triradiates of inner and central part of wall either 

 sagittal, with facial angle of about 140°, the rays as in the surfacc- 

 spiculcs, or subregular, the angles being about 120° each and the 

 lateral rays slightly unequal : in both cases the lengths and diameters 

 of the rays as in the surface-spicules. Eays of triradiates, except 

 in the case above mentioned, almost straight, tapering from base to 

 point. (3) Linear spicules of general body-wall, stout, fusiform, 

 acerate, slightly curved, tapering equally to similarly sharp points 

 at both ends; size -65 by '032 millim.; scattered singly at right 

 angles to surface, points not projecting except at peristome slightly. 

 (4) Fine acerate ? of peristome, length probably about *22 millim., 

 thickness -0032 millim. ; closely aggregated at outer surface, at right 

 angles to surface (the inner end is sharp, the outer end has not been 

 observed). Canals leading from cloacal cavity small : chambers of 

 canal-system small, inconspicuous. Spicules of centre of wall densely 

 aggregated. 



Hob. Providence Reef, Mascarene group, 24 fins. ; bottom, sand 

 and dead coral. 



A single specimen, imperfect at both extremities, represents the 

 species. It is 25 millim. in height, and consists of a short common 

 stem and of two branches, little inferior to the stem in diameter, one 

 of them even increasing in diameter towards its termination. 



Prom the occurrence of the fine linear spicules in some of the first 

 sections which were made it is inferred that they were from a peri- 

 stome, which was probably almost as wide as the tube and had a 

 slight fringe. The occurrence of a few quadriradiates has been 

 observed also in the only species assigned by Hackel to the genus, 

 viz. L.jmlvinar, Hackel; and thus, if Hacker's terms were em- 

 ployed, this specimen would be distinguishable as a " connecting 

 variety " under tho name Leucandra anguineus. This species is 

 markedly distinct from L. pidvinar in its slender form, in the 

 relatively small size of the acerate spicules of the body-wall, and in 



* Anguinens, snake4ike, from the elongate pliable character of the specimens. 



