280 Mr. H. J. Carter on the Sarcohexactinelltd Sponyes. 



the extremity of the smooth anchoring-spicule, since in Euplec- 

 tella, Hyalonema^ Holtenia^ and Meyerina^ whose anchoring- 

 tufts respectively are composed of the two kinds of spicule, viz. 

 smooth, and spin{ferous,\h.Q termination of the extremity in the 

 former appears to he always absent. In none of these sponges 

 have I ever been able to find it ; and my examinations have 

 often been repeated in different specimens varying in size 

 from a quarter of an inch, in some of those dredged up on 

 board H.M.S. ' Porcupine,' to the adult forms obtained from 

 tliis and other sources. The hooked extremity of the sjmii- 

 ferous anchoring-spicules in all the sponges last-mentioned I 

 have been able to obtain, but never one of the smooth anchor- 

 ing-spicules until I came to the specimen of Laharia under 

 consideration, wherein both smooth and spiniferous anchoring- 

 s])icules still, to a great extent, retain their respective hook- 

 like terminations. 



It has been already stated that the double hook at the end 

 of the smooth anchoring-spicule in Laharia has twice the 

 spread of that terminating the spimferous one ; and if this were 

 the case in Ilyalonema and Meyerina respectively, where the 

 smooth anclioring-spicules so much exceed the others in size, 

 as well as in Euiilectella and Holtenia^ wliere they are all 

 much longer and larger than in Laharia^ it is no wonder that 

 they were left in the mud where these sponges originally 

 grew, or were subsequently broken off by " smoothing down 

 the root-like lock," to make it look more beautiful ! or, indeed, 

 torn off by the ruthless "tangle." 



Still further, with reference to the terminal hooks of the 

 spiniferous anchoring-spicule of Laharia, I think I can 

 perceive a microscopic difference in form between them and 

 those of Meyerina, which they so much resemble, that might 

 be given in a figure more satisfactorily than it can be de- 

 scribed, because it is so trifling. But however close the 

 resemblance may be here, the difference between the ter- 

 minations of these spicules in Laharia and those of Holtenia, 

 and of Pheronema Grayi as figured by Mr. Kent (Monthly 

 Microscop. Journ., Nov. 1870, pi. xiii. hg. 16), is so strongly 

 marked that it is impossible (of course, under the microscope) 

 to confound the two, — that of Hottenia and Pheronema Grayi 

 being in the form of a harpoon, while that of Laharia tends 

 to the form of a crescent ; that is to say, the spines of the 

 double hook in the former are much recurved, while in the 

 latter they are much more expanded. I do not wish to insist 

 upon these differences strongly, but state them only as the 

 result of my examinations. 



So rare is it to find any of the spicules composing the cord 



