HYDROCORALS OF THE NORTH PACIFIC FISHER 517 



A. brochi and A. stejnegeri, which have narrow cyHndrical gastro- 

 pores, differ from A. solida in the different type of colony, the notice- 

 ably convex ampullae. A. stejnegeri has rugose ampullae and a much 

 smaller gastrostyle. A. brochi has deep-cut dactylotomes with de- 

 current ridges on sides of gastropore, a deeper, curved gastropore, and 

 relatively smaller gastrostyle. 



A. solida differs from A. verrilli in its narrower gastropore, that of 

 verrUli being wider at mouth than the length of dactylotomes, and 

 funnel shaped, not cylindrical. Its dactylotomes are characteristically 

 constricted between dactylopore and gastropore as in A. calijornica. 



ALLOPORA BROCHI. new species 



Plate 42, Figures Z-Sd; Plate 44; Plate 45, Figure 1 



Diagnosis. — Colony buff pink, small, with robust blunt branches 

 produced in all directions, and without a definite front and back; 

 cyclosystems well spaced, protuberant, distributed on all surfaces; 

 differing from A. solida in the projecting cyclosystems, deeper gastro- 

 pore, deeper dactylotomes, and more conspicuous, low-convex am- 

 pullae. 



DescriiAlon. — The form of the colonies is typical of a heavily built 

 Allopora as the protuberant cyclosystems are about evenly distributed 

 on all sides of the thick branchlets, which are somewhat flattened or 

 compressed, with truncate and rounded ends. Type, 80 mm high; 

 50 mm greatest width. 



The cyclosystems resemble those of trachystoma but are smaller, 

 and the septa do not encroach so much upon the gastrostome. The 

 dactylotomes, commonly 7 to 10 in number, are narrow and deep, 

 and the dactylopore is rather occluded, as indicated in plate 42, 

 figure 3. The gastropore is deep, narrow, curved as a rule, and of 

 nearly uniform width (pi. 42, fig. 36). As m trachystoma the septa are 

 continued as low ridges far down the side of the pore, which is smooth, 

 except for a variable number of small, scattered spicules at the lower 

 end. This style chamber is not sharply differentiated from the part 

 above. The gastrostyle is medium slender, but sometimes a short 

 conical one is found as if it might be regenerating, although no injury 

 to the pore is apparent (pi. 42, fig. 3^). The gastrostyle, surrounded 

 by narrow, interrupted lacunae, may be traced into the coenosteum 

 for a distance equal to its own length. Diameter of cj^closy stems 

 0.68 mm to 1.2 mm; depth of gastropore 1.8 mm to 2 mm; style, 

 0.5 to 0.6 mm. 



The female ampullae are evenly low-convex, with a granulated 

 surface (pi. 42, figs. 3a and 36). The dorsal wall is rather thick, and 

 the inner surface is pitted and fenestrated but not spiculate. The 



