450 Mr. H. J. Carter on 



Halichondria pustulosa, Carter (dry). 



JTalichondna pusfuhsa, ' Annals/ 1882, vol. ix. p. 285, pi. xi. fig. 1, a-g. 



Specimen small, massive, convex above, about \ in. high 

 by 1^ in. in diameter. Colour light grej. Surface closely 

 overscattered with discoid and pustuliform eminences com- 

 posed of linear spicules extending from the circumference to 

 the centre, which can thus, by being raised or depressed, be 

 opened or closed as occasion may require ; each presenting 

 a poriferous area charged with the flesh-spicules of the species, 

 or a simple oscular hole for a vent, as the case may be ; in all 

 respects the same as the Falkland-Island specimen (0^9. etloc. 

 cit.), but with the large acuate spicule smooth instead of 

 spined, and the " tibiella " or straighter spicule for the most 

 part obtuse or only slightly inflated at the ends. 1 did not see 

 any bihaniates, but then these were very scanty in the 

 Falkland-Island specimen. 



Halichondria compressa (incertge sedis). 



Massive, erect, compressed ; thick, with wide flat border ; 

 longitudinally convex, contracted towards the base or point 

 of attachment. Consistence subcompact. Colour sponge- 

 yellow. Surface even, covered with a cribriform dermal 

 structure composed of small spiniferous spicules, circum- 

 scribing the pores and vents respectively, the former chiefly 

 coniined to the sides and the latter entirely to the flat 

 border. Structure subcompact, consisting of sarcode densely 

 charged throughout with spiniferous spicules in the midst 

 of fibre chiefly composed of smooth ones^ the whole plenti- 

 fully traversed by the canals of the excretory systems. 

 Spicules of two kinds, both acuates, but the larger smooth 

 and the smaller remarkably spinous : — 1, smooth spicule, 

 acuate, long, curved, fusiform, subcapitate, abruptly pointed, 

 50 by l-6000th in. ; 2, spiniferous, acuate, curved, remarkably 

 prickly from the size, number, and unequal length of the 

 spines, which cover the whole of the shaft, 26 by 3-6000ths 

 in., including the spines, which, base to base on both sides, 

 are together equal to the transverse diameter of the shaft. 

 No. 1 is confined to the fibre and no. 2 chiefly to the sarcode, 

 especially on the surface, but is sometimes mixed with no. 1 

 m the fibre, and sometimes appears to be arranged in a linear 

 form by itself; very abundant thoroughout. No flesh-spicules, 

 that is anchorates or bihamates, while the spiniferous spicule, 

 although chiefly confined to the sarcode, seems to be too large 

 to be considered a flesh-spicule. Size of largest specimen 



