HYDROCORALS OF THE NORTH PACIFIC — FISHER 503 



The male ampullae are small, rounded-subconical, and densely 

 crowded on both front and back of the branchlets, and overflow upon 

 parts of the front of the principal stems; diameter 0.4 to 0.5 mm. 

 The female ampullae are more spherical than in polyorchis and more 

 decidedly rugose. The walls are deeply grooved, or the grooves are 

 interrupted to form short irregular knobs connected by low ridges. 

 The base of the ampulla is constricted, the wall thin, and the inner 

 surface porous but not deeply fenestrated. Diameter of a female 

 ampulla 0.75 to 0.85 mm, usually the latter. 



Coenosteum smooth, hard, not appreciably different from that of 

 polyorchis in texture. There are no thorny outgrowths. 



Color pale buff, becoming pinkish buff after cleaning with sodium 

 hypocldorite. 



Type— V.S.N. M. no. 43267. 



Type locality. — Station 3480, Amukta Pass, Aleutian Islands, lat. 

 52° 06' N., long. 171° 45' W., 283 fathoms, black sand, rocky. 



Specimens examined. — The type (fragment of female colony), the 

 para type, and two other fragments of a male colony. 



Remarks. — Tliis species has been contrasted with Allopora poly- 

 orchis since the two were taken at the same station and in early stages 

 of my study were confused. However, polyorchis belongs to Allopora 

 according to the standards now used to discriminate the group, 

 whether as a genus or subgenus; cancellatus is very definitely not a 

 form of S. eximius; nor do I believe it can be biigadcd with S. gem- 

 mascens. 



Genus ALLOPORA Ehrenberg 



Allopora Ehrenberg, Abh. Akad. Wise. Berlin, 1832, pp. 303, 371, 1834 (type: 



Allopora oculina Ehrenberg). 

 Stylantheca Fisher, Ann. Mag. Nat. Hist., ser. 10, vol. 8, p. 395, 1931 (type: 



Stylantheca porphyra Fisher). 



ALLOPORA POLYORCHIS, new species 



Plate 36, Figures 1-ld; Plate 37; Plate 38 



Diagnosis. — Colony large, flabellate, with robust anastomosing 

 main stems, and very numerous irregular branches, some of which 

 coalesce with neighbors, the very irregular interspaces being narrower 

 than the branchlets. Cyclosystems crowded, often confluent on 

 sides of branches, numerous but spaced on front, sparse on back. 

 Cyclosystems resembling those of A. campyleca but smaller, the gas- 

 tropores generally straight on exposed front and back of colony and 

 style chamber differentiated by a circlet of spicules; female ampullae 

 with shghtly rugose walls. 



Description. — For form of colony, see plate 37. Its greatest 

 breadth is 390 mm; height about 280 mm. Anterior and posterior 

 aspects v.-eil differentiated, the branchlets arising from anterolateral 



