214 DE. HINDE AND MB. HOLMES ON SPONGE-EEMAINS 



appear as if hooked ; whilst fig. 7 is an oblique view of a small 

 form in which the axial canal of the shaft appears to be supple- 

 mented by canals in the anterior palms. These spicules approach 

 nearer to those of the recent species Guitarra fimhriata, but the 

 mature forms appear to be distinctly larger, and they may be 

 considered as indicating anew species, O. intermedia. 



Ihese peculiar forms of anchorate spicule were first discovered 

 by Mr. Carter in a sponge from the depths of the North Atlantic 

 dredged up by the ' Porcupine ' Expedition (Ann. & Mag. Nat, 

 Hist. s. 4, vol. xiv. 1874, p. 210, pi. xiii. figs. 2-5, pi. xv. fig. 34), and 

 they were subsequently found by Osc. Schmidt in a sponge from 

 the Grulf of Mexico, at the depth of 95 fathoms (Mexico Spong. 

 3 Th. p. 84, t. ix. fig. 7). They have not previously been met 

 W'ith in the fossil state. Mr. Carter's explanation of the hour- 

 glass form as resulting from flattened lateral palms connected 

 together above and below is quite borne out by our fossils, for, 

 as already mentioned, in one instance (fig. 3) the shaft proper of 

 the spicule is shown distinct from the lateral wings, and this shaft 

 has the axial canal extending through it. The only skeletal 

 spicules in the recent Guitarra fionliriata are straight aceratesi 

 without any distinctive features. 



Anchorate JF'Zes^-^2ci<Zes o/^ Pseudohalichondria, Garter. 



The spicules described below belong to a peculiar type of 

 anchorate characterized more especially by an unequally expanded 

 shaft and the presence of numerous spines and protuberances 

 both on the shaft and the teeth or palms. In some instances 

 the spines are so developed that the anchorate character of the 

 spicule is masked and it has the appearance of a spinispirular 

 flesh-spicule. As a rule the shafts in these spicules are strongly 

 curved, so that viewed laterally they are G-shaped. The only 

 recent sponge with anchorate flesh-spicules at all comparable 

 with these fossils is Fseudohalichoiidria clavilohata, Carter (Ann. 

 & Mag. Nat. Hist. s. 5, vol. xviii. 1886, p. 454, pi. x. figs. 8 a, d% 

 from the Australian seas, and they are threfore placed in the 

 same genus. 



FseudohalicJiondria deformis, n. sp. — PI. XI. figs. 8, 9. Spicules 

 equianchorate, subpalmate, with robust, curved, inequally expanded 

 shaft with projecting knobs and protuberances ; lateral palms 

 tongue-shaped, uneven, irregularly spined; anterior tubercles 



