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Show 1881.] THE SURVEY OF H.M.S. ' ALERT.' 103 its specific distinctness. It differs from the rest of the genus in the number of its septa. ALCYONARIA. PRIMNOELLA AUSTRALASIA, Gray. Primnoa australasice, Gray, P.Z.S. 1849, p. 146, Radiata, pi. ii. figs. 8, 9. Primnoella australasice, Gray, P. Z. S, 1857, p. 286. A single specimen, about 54 centims. long; in spirit. It agrees well with the numerous specimens already in the Museum. Close to the present base (which, however, is not the original base, as it has been snapped off from a longer specimen) an empty shark's egg is attached ; its two fastenings having, apparently, modified the growth of the cortex at their point of attachment. Hab. Trinidad Channel, S.W. Chili, 30 fathoms, sandy bottom. HYDROZOA. HYDROIDEA. LAFOEA DUMOSA, Fleming. Sertularia dumosa ?, Montagu ap. Fleming, Edin. Phil. Journ. ii. p. 83. Lafoea dumosa, Hincks, Brit. Hydr. Zooph. i. p. 200, ii. pi. xli. fig. 1. Abundant in the creeping form. The calicle is simple, or else possesses from 1 to 4 rings (old mouths) at different heights. Hab. Trinidad Channel, S.W. Chili, 30 fathoms, on Sertularella. E U D E N D R I U M A R B U S C U L U M , d'Orbigny? (non T. S. Wright). Tubularia arbuscula, d'Orbigny, Voy. Amer. merid. p. 28, pi. xiii. figs. 11, 12. The lower part of the stem is made up of contorted tubes, and the colony resembles E. rameum closely in external appearance; and is apparently nearly related to it. D'Orbigny makes the stem of about one diameter throughout, but as in the magnified drawing he depicts part of it as thicker than the part below it, which is contrary to analogy, it does not follow that his other figure is correct ; according to that, the origin of the branchlets is dorsal or ventral, not lateral, and they take a twist to the side on leaving it. The stem in the present example is always ringed between the branches, though to a varying extent, and the branchlets are annulated for most of their length. Characters of polypites and gonophores unknown. Maximum height about 80 millims. Several colonies occur together. Hab. Trinidad Channel, S.W. Chili, 30 fathoms, from stem of seaweed? HALECIUM DELICATULUM, Coughtrey. Halecium delicatulum, Coughtrey, Ann. & Mag. Nat. Hist. ser. xvii. p. 26, pi. iii. figs. 4 & 5. Several colonies, of 27 millims. height, appear to represent the above |