COLLECTED ON THE ' CHALLENGER ' EXPEDITION. 345 



In some respects the characters of this form render it doubtful 

 whether it may not be a variety of C. bispinata, B.M. Cat., or 

 G. (Discopora) albirostris, Smitt (Florid. Bryoz.) ; but the total 

 absence of any sign of the two long slender oral spines in the mar- 

 ginal zooecia, and the different form and proportions of the preoral 

 rostral process, render them, in my opinion, sufficiently distinct. 



2. C. APICFLATA, n. Sp.* 



Char. Zoarium incrusting, or unilaminar and unattached. 

 Zooecia (at the growing edge) ventricose or barrel-shaped, with a 

 granular unpunctured surface ; in the older portions deeply 

 immersed and very confusedly disposed, varying much also in 

 size. Primary orifice semicircular, with a straight entire lower 

 border, aud surmounted in the earliest stage by two, or rarely 

 three, long oral spines. Preoral rostrum very irregular in size, 

 and supporting usually on one side a large avicularium, with an 

 obtuse serrated beak, and a subacute lanceolate or triangular 

 mandible, and usually produced beyond the avicularium into a 

 longer or shorter obtuse apiculate spine. 



Sal. St. 163 A. Off Port Jackson, 30-35 fms., rock. 



The extreme irregularity of growth and great diversity in the 

 form and size of the preoral rostrum, which is sometimes very 

 small and at others developed into a very large avicularian pro- 

 cess, renders any description of this species very difficult. The 

 chief points at present are : — (1) the semicircular orifice (about 

 0""07 wide) with a straight entire lower lip ; (2) the, at first, short 

 and thick hollow rostrum, which afterwards becomes produced 

 into an obtuse spine, and on the side of the wider portion, some 

 distance above the base, supports on one side a large avicularium 

 with a finely serrated beak and rather blunt elongated mandible ; 

 (3) the presence on the youngest zooecia only of two, or sometimes 

 three, long oral spines, like those in G. bispinata, mihi, or C. 

 albirostris, Smitt. The figure in " Chalk Bep." plate xxix. has 

 unfortunately been taken from a very bad specimen, and shows 

 little of the real characters. 



3. C. nodtjlosa, n. sp. 



Ghar. Zoarium a rounded, irregularly nodular massive growth. 

 Zooecia perfectly upright, very deeply immersed below, often free 

 above, and united in sets of three or four together. Orifice 

 suborbicular or elliptical, about 0""007 wide. A few excessively 

 minute denticles within the lower border. Operculum subtrian- 

 * " Ohall. Rep." pi. xxix. fig. 2. 



