110 



species appear avicalaria, which are generally capitate and pedunculate or trumpet- 

 shaped. The radical fibres, which run down along the basal side of the colony 

 issue far distally on the individual zocecia. The colonies are elegant tufts with 

 biserial branches. 



This genus which will most probably be split up later into several includes 

 the majority of the species in the old genus Bicellaria\ and the only species 

 known to me which remains in this genus is B. ciliata. One of the characters 

 which, in a narrower sense, separates the genus Bicellaria from Corimcopina, is 

 the sharp constriction between the wider funnel-shaped terminal portion of the 

 zooecium and the proximal cylindrical portion, and Cornucopina grandis in this 

 structural feature approaches Bicellaria, as we find at the same place internally 

 a narrow, ring-shaped, oblique, chitinous thickening. This species also occupies 

 a special position within the genus in having a cryptocyst (fig. 5 a), already ob- 

 served by Harmer^, which extends under the larger part of the frontal mem- 

 brane and reaches almost to the operculum. It is provided with finely curved 

 and dentated edges, and it rises distally from the deeper, proximal part to end 

 in a free, shovel-shaped plate. Two successive zocecia are connected by a multi- 

 porous rosette-plate, which is surrounded by a calcareous ring, and this is again 

 connected with a similar ring surrounding the adjacent rosette-plate of the lateral 

 wall (fig. 5 a — 5 b). Busk has overlooked the very large plump avicularia, which 

 in this species here and there issue from the basal surface of the zocecia a little, 

 proximally to the outer margins (fig. 5 c). 



Beania Johnston. 

 Diachoris. 



The very slightly calcified zocecia are mutually connected by cylindrical tubes 

 to a more or less open network, which is attached to the underlayer by radical 

 fibres arising from the basal surface of the individual zocecia; each tube is furn- 

 ished with a multiporous rosette-plate; no ooecia; as a rule freely movable 

 avicularia. 



While all the species, which 1 have been able to examine of this genus, have 

 an operculum, such according to Busk's' account and figures, is lacking in 

 Diachoris magellanica, in which the aperture is said to be surrounded by a circu- 

 lar thickened rim. If this account is correct, this species must probably be re- 

 garded as the representative of a special genus, and this might then retain the 

 old name Diachoris. — In the species from Rapallo, which Waters calls B. 



' 8, p. 31. ^ 19, p. 326. 



