NO. 1 DURHAM, BARNARD: EASTERN PACIFIC STONY CORALS 87 



Distribution: Sta. 1027-39 is 5 mi southeast of Santa Catalina 

 Island, 140-150 fms; Sta. 1848-49 is 4 mi southeast of east end of Santa 

 Catalina Island, 104-135 fms. 



Genus HETEROGYATHUS Milne Edwards and Haime 



Heterocyathus Milne Edwards and Haime (1848), Ann. Sci. Nat., 

 ser. 3, vol. 9, pp. 323-324. 

 Genotype: Heterocyathus aequicostatus Milne Edwards and 

 Haime. 



Heterocyathus aequicostatus Milne Edwards and Haime 



Plate 11, figs. 49a-d 



Heterocyathus aequicostatus Milne Edwards and Haime (1848), Ann. 



Sci. Nat., ser. 3, vol. 9, p. 324, pi. 10, fig. 8. 

 Heterocyathus aequicostatus Ed. and H., Gardiner (1905), Mar. Invest. 

 So. Africa, vol. 3, pp. 105-112, pi. 3, figs. 1-43. 



Description of hypotypes: Corallites ceratoid to trochoid, in groups 

 of 3 or 4 attached to gastropod shells, with commensal worm tubes in 

 base; calices circular, very shallow; height 8 mm, diameter of calice 

 5 mm, calice 2 mm deep; septa 30-40, arranged in a Pourtales plan 

 which is obscured by a large papillary columella; septal interspaces 1.0- 

 1.5 times as wide as thickness of primary septa; septa with 2-4 even- 

 sized, short, paliform lobes, columella composed of similar interlacing 

 processes, very spongy deep within the calice ; later cycles of septa highly 

 perforated toward columella; septal margins above paliform lobes den- 

 tate ; septa well-rounded above, descending obliquely into shallow calice ; 

 primary septa most exsert, other cycles successively less exsert, fourth 

 cycle septa adjacent to first cycle septa almost as well-developed as the 

 latter ; granules of septal faces variable in development, sometimes heavy 

 enough to almost obliterate the interseptal spaces, on other specimens 

 only slightly developed ; costae minutely granulated, subequal in width, 

 rounded, occasionally V-shaped ; costae of first 3 cycles usually more 

 elevated ; costae of all cycles extending to base on some specimens, on 

 others becoming indistinct; costal interspaces one- fourth to one-third 

 the width of the costae, somewhat flat-bottomed. 



Remarks: Gardiner's Plate 3, figs. 39 and 43 (1905) are particu- 

 larly representative of the material in the present collection (L.A.C.M. 

 A375). The large variation seen in Gardiner's material is not evident 

 here. In Harrison's classification (1911, p. 1025) these specimens would 



