292 Mr. T. Higgiu on some Caribbean Sponges. 



reticulation, in wliich the spicules are held firmly in position 

 by tough hardened sarcode, not generally enclosed in this 

 horny material, but cemented together by it where they touch 

 or cross each other, the fibre being echinated by smooth 

 spicules wliich project from its interior into the interstices at 

 various angles, and the surface hirsute. Spicules of two 

 kinds — namely, smootli acerates forming the skeleton-structure, 

 and spined acerates, chiefly confined to the sarcode and the 

 surface of the sponge. The skeleton-spicule is a smooth, 

 stout, curved acerate, whose ends are slightly bent outwards, 

 measuring 0'02o inch in length by 0*001 inch in the middle, 

 its strongest part (fig. 2) , associated with which are fine slen- 

 der straight acerates in small quantity, sometimes longer than 

 the others, measuring only 0"0002 inch in diameter (fig. 3). 

 The spicules of the sarcode are likewise acerate and only 

 slightly bent, variable in size, but averaging in their largest 

 forms 0*008 inch in length by 0*00025 'inch in diameter in 

 the middle, found generally throughout the sponge, but espe- 

 cially in the furro\\s of the surface, where they are congregated 

 together in masses and lie in a horizontal position. 



Size of specimen 7 inches in height, with a similar breadth ; 

 length of stem from basal attachment to first lateral projection 

 1\ inch, diameter of stem 1 inch by \ to |, diameter of flabel- 

 late portion ^ to -g- inch. 



Colour, in its present dried state, cream-white. 



Loc. Carinage Harbour, Grenada, West Indies. 



This beautiful sponge, which is the only example of the 

 species in the ' Argo ' collection, was obtained by the Rev. H. 

 H. Higgins from Mr. Thomas G. Rowley of St. George's, 

 Grenada, and is said to have been got by diving. As regards 

 its skeleton, it is in excellent preservation and very perfect ; 

 but it has been carefully cleaned and consequently has lost 

 much of its sarcode, together, probably, with many of the 

 spined acerates, which in the living state existed in large 

 quantities in the form of a matted surface-covering, since, as 

 before stated, masses of them still remain in tlie furrows. 



Although this sponge is the only example of the species in 

 the ' Argo ' collection, the genus is represented by other speci- 

 mens in the Liverpool Museum, and also by several sponges 

 from South Africa in the British Museum. In all cases the 

 skeleton-structure is made up of smooth spicules, either of the 

 acerate form only, or of acerates and acuates in varying 

 quantities, more or less bent rather than curved in the centre ; 

 and the fibre is always more or less echinated, the spicule of 

 the sarcode being in every instance a spined acerate. 



All the specimens so far known are, with one exception, 



