REPORT ON THE HEXACTINELLIDA. 337 



Genus 5. Sclerothamnus, Marshall (PI. XCVIIL). 



1875. Marshall, Zeitscbr. f. wiss. ZooL, Bd. x.vv., Suppl., p. 171. 



1876. J. Murie, Trans. Linn. Soc. Lond. (ZooL), ser. 2, vol. i. 

 187G. Carter, Ibid., Appendix. 



History. — The term Sclerothamnus clausii was applied by Marshall ' to a bushy- 

 branched Hexactinellid obtained from an unknown source. It measured 50 cm. in 

 height, while the cylindrical branches, which were repeatedly forked, had a diameter of 

 3 "5 cm. towards the extremities, and of 13 cm. at the basal ends. In the tolerably 

 uniform framework of siliceous beams, which consists of fused hexradiate sj)icules with 

 tubercled external surfaces, Marshall thought he perceived a continuous connection 

 between the axial canals, which exactly met one another in the fusion of adjacent hex- 

 radiate spicules, and thus remained in open communication. The broad (5 mm. in 

 diameter) and narrow (1 mm. in diameter) canals, which traverse the branches of the 

 sponge, often anastomose with each other, and open outwards by orifices of variable size. 

 Many of these excurrent passages, moreover, possess a fringe in the form of a freely pro- 

 jecting cuff, but on the whole the canal system seems to be indistinctly and irregularly 

 developed in the dense tissue. 



Among free spicules Marshall found (1) large-knobbed hexradiate forms, which fuse to 

 form the continuous framework ; (2) very small fine regular hexradiate spicules ; (3) 

 broom-forks with five clubs, beset with delicate warts on each of the expanded portions, 

 while their stalk, which is covered with similar warts down to a slisfht swellinsf, ter- 

 minates in a short point; (4) longer broom-forks (Besengabeln) with four long clubs, in 

 which the stalk, like the spicular shaft, is beset with fine recurved booklets. 



In the following year, 1876, there appeared in the Transactions of the Linnsean 

 Society (Zoology), ser. 2, vol. i., a detailed paper illustrated by numerous good figures, 

 On Steere's Sponge, a New Genus of the Hexactinelbd Group of the Spongidse, by James 

 Murie. This bushy branched Hexactinellid was procured by natives from a depth 

 varpng from 80 to 100 fathoms in the neighbourhood of the Philippines, " between the 

 strip-like and parallel islands of Negros and Cebu." In its dried state it measured about 

 80 cm. in height, and exhibited branches as thick as one's finger. The form is accurately 

 described under the name of Dcndrospongia steerei. Professor Steere had bought this 

 beautiful specimen during his stay in the Philippines from fishermen " on the opposite 

 eastern side of the island of Cebu, where no sponges are said hitherto to have been got 

 from the sound or channel above-mentioned." Murie reports ^ — " One day, while in the 

 forest, Professor Steere was suddenly apprised of the arrival of the Challenger Expedi- 

 tion by a note from Professor AVyville Thomson, who had heard of him and his where- 

 abouts. He hastened on board, passing, as he assures me, a most agreeable day in the 



' Zeitschr.f. vnss. ZooL, Bd. xxv., Suppl., p. 171, 1875. 



' Loc. cit., p. 221. 



(zOOL. CHALL. EXP. — PAKT LHI. — 1887.) -Ggg 43 



