1907.] FROM TUE CAPE YEKDE ISLANTJS. [65] 



the same varuibility occurs, those on the proximal hydrothecre 

 rLsiug just clear of the margin, those in the distal produced into 

 long, prominent " horns" re^icliing O'l mm. beyond it. Tiiey have 

 two apertures, one terminal, the other lateral and just above the 

 hydrothe&a margin. The cauline nematophores, of which there 

 are two on each hyth-oclade-bearing intemode, one on a level with, 

 the other proximal to, the base of the hydi-oclade, are large, from 

 O'l to 0'2 mm. in height, and triangular. 



The colonies are of a rich dark brown colour which, however, 

 is almost lacking in the more delicate hydroclades. 



The gonosome is not present. 



The specimens here described, although they differ from 

 L. grandis (CLirke, 1879) in their unilateral mode of branching, 

 agi'ee so accurately with the minute structure of hydi'otheca and 

 branch as desciibed and figured by Vei-sluys (1899, p. 51), that 

 they have been referred to that species. The black gi-auulai- 

 pigment-cells observed by Nutting (1900) in the ccenosarc of 

 ■L. grandis and L. clarkei are present in considei'able numbers in 

 my specimens. The branching here described is similar to that 

 of L. racemiferus of Allman (1883), but the specimens difler 

 in the greater length of the h3-droclades, the bulging shape 

 of the hydrotheeai, the number of marginal teeth (apparently only 

 five in Allman's figuies), and the presence of a distal iuternodal 

 septum. Allman does not mention the presence of cauline nemato- 

 phores in his species. 



Loml'Uy. St. Vincent, Cape Verde Islands : depth 15 fathoms ; 

 30th July, 1904. 



Lytocarpus crosslaxdi, sp. n. (Plate XXIV. fig. 11 ; Plate 

 XXVI. figs. 2, 3, 4.) 



Colonies unbranched, springing from a creeping hydrorhiza 

 and attaining a height of about 15 mm. The stem is mono- 

 siphonic, divided into regular internodes 0'3 mm. in length, 

 except the proximal millimetre which is undi\-ided, and which is 

 separated from the remainder by a deep constriction sloping 

 downwards from posterior to anterior. The hydroclades, which 

 are boine on each intemode, are placed anteriorly on the stem 

 and are approximate and alternate. They are divided into regular 

 internodes 0'25 mm. long, each of which bears on its anteiior 

 surface a hydrotheca, and contains two septal ridges, one opposite 

 the inti-athecal ridge, the other under the lateral nematophores. 

 In no case was a third septum, between the other two, observed. 



The hydrothecaj are closely approximated, and are marked in 

 front by a deep fold which brings the aperture into a vertical 

 position. The margin has anteriorly a strong, sliai-p, uptiu-ned 

 tooth and on each side a prominent lobe, while the interior is 

 divided into two regions by an intrathecal lidge projecting 

 forwarils from the internode about 0"5 mm. from the bottom. A 

 second stout inti-athecal ridge projects backwards into the hj-dro- 

 theca from between the mesial nematophore and the margin. 



Phoc. ZooL. Soc— 1907, No. XXXV. 35 



d 511 



