1907.] FROM THE CAPE VERDE ISLANDS. 511 



the same variability occurs, those on the proximal hydrothecse 

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

 long, prominent " horns " reaching O'l mm. beyond it. They have 

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

 hydrotheca margin. The cauline nematophores, of which there 

 are two on each hydi'oclade-bearing internode, one ou a level with, 

 the other proximal to, the base of the hydroclade, 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 difier from 

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

 agree so 'accurately with the minute structure of hydrotheca and 

 branch as described and figured by Versluys (1899, p. 51), that 

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

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

 L. grandis and L. clarkei are present in considerable numbers in 

 my specimens. The branching here described is similar to that 

 of L. racemife?-us of AUman (1883), but the specimens differ 

 in the greater length of the hydroclades, the bulging shape 

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

 five in Allmaii's figui^es), and the j^resence of a distal internodal 

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

 phores in his species. 



Locality. St. Vincent, Cape Yerde Islands : depth 15 fathoms; 

 30th July, 1904. 



Lytocarpus crosslandi, sp. n. (Plate XXIY. fig. 11 ; Plate 

 XXYI. 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 undivided, and which is 

 separated from the remainder by a deep constriction sloping 

 downwards from posterior to anterior. The hydroclades, which 

 are borne on each intei-node, ai-e placed anteriorly ou the stem 

 and are approximate and altei-nate. They are divided into regular 

 internodes 0*25 mm. long, each of which bears on its anterioi- 

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

 the intrathecal ridge, the other under the lateral nematophores. 

 Tn no case was a third septum, between the other two, obsei^ved. 



The hydrotheca? are closely a23pi'oximated, and are marked in 

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

 position. The margin has anteriorly a strong, sharp, upturned 

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

 divided into two regions by an intrathecal ridge projecting 

 forwards from the internode about 0*5 mm. from the bottom. A 

 second stout intrathecal ridge projects backwards into the hydro- 

 theca from between the mesial nematophore and the margin. 



Proc. Zool. Soc— 1 907, Xo. XXX Y. 35 



