148 Mr. H. J. Carter on Specimens 



ences the subsequent development of the fully formed spi- 

 cules of this Lithistid even to the end (fig. 49, A), in which 

 the filigreed terminations are not grape-like as in the fore- 

 going species, but subangular (fig. 49, i). Papilla at first 

 microscopic, then enlarged, after which they become united 

 by intervening straight linear ridges, then elevated and com- 

 pressed, and finally divided into spine-like processes (fig.49,<7), 

 which more or less characterize the fully formed spicules 

 (fig. 49, h). Flesh-spicule acerate, curved, microspined, about 

 5-6000ths long (fig. 49, e), plentifully distributed over the 

 disks (fig. 49, a) and throughout the structure. Size about 

 1 inch in horizontal diameter, filling up the depressions on 

 one side of a Melobesian nodule about this size. 



Hob. Marine. On hard objects. 



Loc. Gulf of Manaar. 



Obs. The asperous character of the spiculation of this 

 species, arising from a transformation of the original papillae 

 of the disk into spinous processes, as above mentioned and 

 illustrated (fig. 49, (/, &c), chiefly distinguishes it. As the 

 specimen for the most part is very much worn, I should, but 

 for the boiling in nitric acid of a portion which had been pro- 

 tected by having been overgrown by a Beniera, have been 

 entirely ignorant of its discophorous character and the peculiar 

 spinous transformation of the papilla? of the disks to which I 

 have alluded, which seems to continue its influence on to the 

 fully formed structure. 



Discodermia sjnnispirulifera, n. sp. 

 (PI. VIII. fig. 50, a-h.) 



Surface even, discophorous ; disks horizontal ; structure 

 loose, accompanied by two forms of flesh-spicule, viz. an acerate 

 and a spinispirula (PI. VIII. fig. 50, a, b, c, and e,f). Colour 

 white. Discophorous structure and transformation much the 

 same as in the foregoing species, only that, instead of papillae, 

 the disk presents faint circular concentric lines (fig. 50, d), and, 

 previously to passing into the branched form, show an irregu- 

 larly lacerated margin in which the foreshadowed divisions of 

 the full-formed spicule assume the most whimsical proportions 

 and appearances (fig. 50, i), finally producing a branched 

 spicule repeatedly subdivided as before until the ends become 

 filigreed into subglobular processes (fig. 50, g). Flesh- 

 spicule of two forms, viz. : — 1, comparatively large, acerate, 

 curved fusiform, microspined, about 20-6000ths inch long 

 (fig. 50, e) ; and the other, 2, a minute spinispirula, consisting 

 of a sinuous shaft covered with thin spines about the same 

 length as itself, arranged over it in an echinating, spiral 



