238 THE VOYAGE OF H.M.S. CHALLENGER. 



mentioned. Anchoring spicules of two kinds, viz., smooth and spiniferous, the hitter 

 terminating at its free extremity in a recurved double hook, termination of the former 

 unknown." On the other hand, Laharia hemisplnBrica, though closely allied, is so 

 peculiar as to constitute a section by itself, with the following characteristics : — 

 " Species possessing the birotulate flesh spicule, in which the termination of both kinds of 

 anchoring spicules are known. Free termination of spiniferous anchoring spicules much 

 the same as in the above mentioned ; termination on the smooth anchoring spicule con- 

 sisting of a double hook or arm, opposite, compressed, slightly recurved, and twice the 

 size of the head of the spiniferous form." Carter placed Oscar Schmidt's Holtenia 

 jMurtalesli at a great distance from both of these groups, between Crateromor-pha and 

 Rossella, and characterised it in the following terms : — " Eosette many-rayed ; rays 

 multitudinous, of unequal length, straight and capitate, pappiform." 



As the result of a thorough investigation which Higgin^ was able to carry out on a 

 well-preserved specimen of the Laharia hemisphwrica, Gray, from Cebu, some errors 

 in Carter's earlier description were corrected — errors which were mainly attributable 

 to the fact that the specimen which Carter had studied was mixed up with foreign 

 spicules belonging to another sponge. This was confirmed'* by Carter himself, for he 

 remarks, " that the anchoring spicules with spined shaft are abnormal." Carter also 

 observes, that " while the shafts of the anchoring spicules of Laharia hemisphserica and of 

 the genus Eossella are all smooth, those of Hyalonema, &c., are all spined; and that the 

 latter only appear to be sometimes smooth from the spines being continued upwards 

 from the free end for a less distance in some than in others." 



In his notes on the affinities of the Hexactinellida, Marshall observes, ^ that " Labaria 

 and Pheronema are clearly very closely related to one another, and perhaps scarcely 

 separable generically ; " and further, that ''Holtenia saccus, 0. Schmidt, is also related 

 to Pheronema, though it does not belong to this genus." 



Among the sponges which were collected by the French Expedition of the " Travailleur " 

 in the Bay of Biscay, Norman also records Holtenia carpenteri.* According to the report 

 of Oscar Schmidt,^ a typical specimen of Pheronema annas was found in the neighbourhood 

 of Santa Cruz, at a depth of 180 and 248 fathoms. A special genus LeiohoUdium has 

 been established by Oscar Schmidt for a spherical sponge measuring 1 5 mm. in diameter, 

 soft and smooth to the touch, resembling in general habit and softness a delicate 

 Eeniera, and exhibiting the same microscopic component elements as Pheronema. " At 

 the one pole there is an osculum surrounded by a rim, over against this there is a 

 small irregular depression from which a root-tuft seemed to have been torn." 



' Ann. and Mag. Nat. Hist., ser. 4, vol. xv. p. 385. 



'^Loc. cit., p. 389. 



^ Zeitschr. f. urns. Zool., 1876, vol. xxvii. pp. 113-136 ; vide p. 130. 



* Ami. and Mag. Nat. Hist., ser. 5, vol. vi. p. 436. 



^Die Spongien des Meerbusens von Mexico, 1880, pp. 64, 65. 



