308 Mr. II. .1. Caitor on Deep-sea 



pointed ends, projecting externally, give the hirsute appear- 

 ance to the dermal .^^arcode, -where the points are so arranged 

 in linear network as to present the reticulo-pitted aspect above 

 mentioned. Size of sponge extending from a thin lamina up 

 to 3 inches in height, varying in thickness with the form 

 taken by the sponge. 



Hah. Marine, attached individually to little pebbles. 



Loc. Atlantic Ocean, between the north of Scotland, the 

 Shetland and the Fiiroe Islands, in depths varying from 114 to 

 640 fathoms. 



Ol>s. In form this species only differs from 77. vermicidata, 

 Bk. (which is thin, laminiform, and incrusting, fig.4,c), in being 

 erect or vertical, but in nothing else, further than that the spi- 

 cules appear to be a little larger and tlie vermiculates a little 

 less vermicular in H. erecta. In structm-e, both consist of large 

 acuate spicules, whose pointed ends for the most part project 

 externally, and are tied together internally by a mass of the 

 vermiculates ; while the less degree of vermiculation of the 

 latter in H. erecta^ as well as the tendency to aflabellate form, 

 seems to point out a transition of the latter to PhakelUa venti- 

 lahruni, where the interlacing spicules still retain a little Ver- 

 miculation, until it is lost altogether in P. infundihuUformis, 

 where the shape of the acuate remains, but that of the undula- 

 ting or vermicular spicule has passed into a simply curved 

 acerate, which curve, it should be also remembered, approaches 

 in form to that of a ' bend ' in the centre, ending with Axi- 

 nella. Thus we have a group of sponges extending from the 

 lowest form, viz. HymernpMa venm'ciilata, to jixinella, which 

 may hereafter be found serviceable in dividing the group Multi- 

 formia of my suborder Axinellida in the order Echinonemata. 

 Ilymeraphia vermiculata bears a similar relation to PhakelUa 

 ventilahrum that Microciona atrosanguinea does to HaiicJion- 

 dria plumosa. 



II. erecta is present in several jars, especially in No. 65, 

 whose depth is 345 fathoms, about 40 miles N.W. of the 

 Shetland Islands ; and //. vermiculata is almost always found 

 in company with it. Fragments of PliakeUia ventdahrum 

 and P. infundihuUformis also come from the same localities. At 

 station 51 portions of Geodia^ Stelletta, and Reniera fihidata, 

 Sdt., were dredged up with it ; and at 65, Geodia, Tisiphonia, 

 Donatia lyncurium^ Tricliostemma liemisplicericum^ Sars, Poly- 

 mastia hrevis, Bk., and PhakelUa ventilahrum. 



Both Axinella mastophora^ Sdt., and Auletta sycinularia, 

 Sdt. (Atlantisch. Spongienf. pp. 45 and 61, and Taf. iv. figs. 5 

 and 14 respectively), appear, from the form of their spicules 

 and hirsute surfaces, to be allied to H. erecta. 



