115 



circular, though in such a way that its distal curved edge (the anter) meets with 

 the almost straight proximal edge in two almost parallel lateral margins. The 

 aperture is occupied by a membranous opercular valve with a chitinous rim. On 

 the basal surface in the distal part of the zooecium between the two avicularia 

 we find a small, more calcified, quadrilateral area. 



The avicularia which are placed on each side of the distal part of the zooe- 

 cium, are somewhat strongly compressed with an elongated oval frontal surface 

 which is turned outwards. Seen from the side they are trapez-shaped with a 

 small hook-shaped curve. 



The ooecia are lacking on the branches examined by me, but according to 

 the description (>galeriform, lofty, terminal*) Busk gives, there is hardly any 

 doubt that they are free. 



The colonies have uniserial branches, and from each zooecium issue two new 

 ones, one from the tip, and one from a triangular projection on one (the right 

 and the left in turns) of the lateral walls, a little above the centre of the wider 

 terminal part of the zooecium. 



I have been able to examine a small branch of this species from the Chal- 

 lenger's station 280, which has been kindly placed at my disposal by Mr. Kirk- 

 pa trick from the British Museum. In favour of its reference to this family 

 speak not only the agreements in mode of growth and zooecial form with Brettia, 

 but in still higher degree the free ooecia, since free ooecia do not appear in any 

 other Malacostege family. 



Chaperia Jullien^. 



The distal part of the zooecium is furnished internally with two lateral spaces 

 open towards the frontal surface (sometimes coalesced to a single horse-shoe- 

 shaped one), formed by two plates which project from the side-walls and converge 

 towards the distal wall. Each distal wall has 2 multiporous rosette-plates and the 

 distal half of each side-wall a single one. Hyperstomial free ooecia with a com- 

 pletely calcified ectoooecium. The zooeeia which may sometimes have a membranous 

 opercular valve, sometimes a chitinous compound operculum, are generally strongly 

 provided with spines and have often a well developed cryptocyst. Avicularia 

 sometimes trumpet-shaped, not always present. The colonies are incrusting. 



To this genus belong the following species: Ch. annulus Manz (— Ch. galeata 

 Busk), Ch. cristata Busk, Ch. cervicornis Busk, Ch. cglindracea Busk, Ch. albispina 

 M. Gill.^ Ch. capensis Busk, Ch. patulosa Waters ^ Ch. tropica Waters* etc. 



' 45, p. 61. * 64, p. 116, pi. fig. 10. ^ 115, p. 33. * 116 a, p. 168. 



8* 



