the Submarine- Cable Fau7ia. 17ii 



the hydrothecse in regular verticils, aiul the branchlets con- 

 tracted in a very remarkable manner at their junction with 

 the branches. 



Genus Scapus, Norman, n. g. 



Zoophyte in the form of a spongious mass rolled in cylin- 

 drical form round the stems of branching Hydrozoa [Acrypto- 

 lart'a), and consisting of a series of somewhat closely packed 

 subquadrate hydrothecae, closed in above, except at the centre, 

 where the hydrotheca projected in the form of a short, simple, 

 cylindrical homy tube. 



Scapus tubulifer, Norman, n. sp. PI. XII. fig. 1, a, & fig. 3. 



Zoophyte growing in little roll-like masses round the 

 larger stems of Acryjytolaria exserta (Busk), almost every 

 specimen of which was the bearer of this parasitic species, 

 though none of the other zoophytes procured at the same time 

 and place showed a vestige of it. The roll-like mass has 

 a soft spongious character, the external crust being harder. 

 It consists of a large number of hydrothecae, which, on a 

 section being made, prove to be subquadrate in form, and 

 packed closely together without any interspaces ; the hydro- 

 theca is closed in above except at the centre, where it is raised 

 in the form of a short tubular orifice, rising from the mass of 

 the hydrozoary ; this tube is often slightly, but never much 

 bent. 



At first sight this species bears a strong resemblance to 

 Coppima arcta, from which, however, we at once know it by 

 the more elongated and delicate character of the rolls and 

 by the much shorter tubuli. In organic structure, however, 

 the two species are very distinct from each other. In Cop- 

 pinia the basal mass consists of chitinous cells rendered 

 polygonal by mutual pressure, these cells are the gonothecse ; 

 while the slender-tubed hydrothecae pass through the mass to 

 the base of the hydrozoary, and are of equal diameter from 

 the base to their free extremities (see a paper on the structure 

 of Coppinia by Allman, Brit. Assoc, Report, 1868, p. 87, 

 published subsequently to Hincks's work). In Scapus the 

 basal mass consists of the hydrothecae, which are bottle-shaped, 

 expanded below and forming the mass, and contracted above 

 into narrow projecting tubes. 



SertulareUa polyzonias (Linn.). 



Gayi (Lamx.). 



Diphasia pinaster (Ellis & Sol.). 

 nkita (Hincks). 



