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



Genus Lophogorgia, Milne-Edwards. 



Lophogm-gia, Milne-EJ wards, Hist. Nat. des Coralliaires, vol. i. p. 167. 



Gorgonia, Kblliker (pars), Icones Histiol., p. 139. 



Leptogorgia, Verrill (pars), Amer. Journ. Sci. and Arts, vol. xlviii. p. 425. 



This genus was formed by Milne-Edwards for Gorgonia palma, Esper non Pallas, 

 the Gorgonia jtammea, Ellis and Solander ; it must not be confounded with Gorgonia 

 palma, Pallas, which is a Euniceid, near Eunicella, Verrill. We are not able to follow 

 KoUiker's plan of sinking this and other genera under the common denomination of 

 Gorgonia, and we venture to differ from Verrill, who places Lophogorgia as a section of 

 the emended genus Leptogorgia. 



Lophogorgia is here retained for those Gbrgonids with more or less flattened stems and 

 branches, these latter spreading in nearly the one plane and sometimes being cylindrical at 

 their growing tips. The polyps are retractile within the coenenchyma, without verrucae. 

 The larger nutrient canals are on the flattened portions of the stem to be found on the 

 flattened surfaces, though in the cylindrical twigs they are symmetrical. 



The genus would come next to Leptogorgia. 



Lophogorgia lutkeni, n. sp. (PI. XXX. figs. 1, la ; PI. XXXIV. fig. 1). 



Colony attached by a disc-like base ; branched, branches arising in the one plane. 

 Axis horny, flexible and compressed. The branches, which are also somewhat compressed, 

 are given oS" at irregular intervals, sometimes continuing simple, at other times once 

 again branching. Height of the colony 240 mm., the widest diameter of the main stem 

 is 3 mm., and the principal branches have the same diameter. The main stem and 

 branches are marked on both surfaces with an irregular wavy line. 



The coenenchyma is moderately thick, granular, containing numerous warty double 

 spindles. 



The polyps are numerous and occur on both the stem and branches ; the verrucae are 

 very slightly elevated. The central portion of both the main stem and the branches on 

 both surfaces are destitute of polyps. The polyps are completely retractile. The 

 tentacles are well furnished on their dorsal surfaces with slender needle-shaped spicules. 

 When the polyps are completely withdrawn, the verrucae present the appearance 

 of oblong slits, but there is a considerable difl'erence in their size, the long diameter 

 varying from 1"5 to 2"5 mm. The spicules of the coenenchyma are warty spindles, 

 measuring 0-2-004 ; 0-3-002 ; 0-34-0-02 ; 0-2-0-025 ; those of the tentacles are 

 needle-shaped, feebly spined, sometimes curved, and measure 0'3-0'02 ; 0"12-002; 

 0-22-002; 016-004 mm. 



The colour in spirit is a dull yellowish-red. 



Habitat. — Station 145a, ofi" Prince Edward Island; depth, 310 fathoms. 



