36 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 16 



what worn. Slightly developed lateral septal ledges may be present. 

 Better material may show that these specimens represent a new species. 



Vaughan's material came from the Hawaiian Islands, depth 13-43 

 fms. Matthai (Mem. Ind. Mus., vol. 8, no. 1, p. 52, 1924) records 

 it from the Andaman Islands, 15 fms. 



Hypotype: Cat. no. 10. 1 (Sta. 23-33). 



Material examined: Sta. 23-33 (1). Bottom samples 306 (1), 329 

 (frag.), 541 (frag.). Cat. nos. 10.1-10.4. 



Distribution: La Plata Island, Ecuador; Grorgona Island, Colom- 

 bia; Chatham Bay, Cocos Island. Bathymetric range, 10-46 fms. 



Leptoseris panamensis Durham and Barnard, new species 



Plate 2, figs. 11a, b 



Corallum small, digitiform, the branches thicker orally to adorally 

 and more slender than in Leptoseris digitata Vaughan, with the edges 

 not as curled as and more rounded than in that species, margins of 

 branches not lobed (similar to L. gardineri van der Horst) ; calices uni- 

 facial, varying from 1-4 mm apart, averaging 0.75 mm in diameter, 

 superficial in appearance except in the crotches of branches where they 

 are deeper; septa 12-14 per calice (excluding 8-12 marginal septocostae 

 per calice), all approximately equal in size, interspaces twice as wide as 

 thickness of septa; septa with projecting lateral shelves or ledges com- 

 posed of fused granules, margins of ledges dentate; ledges more highly 

 developed on septa which reach columella; near the latter, the septa 

 superficially appear to be 3-4 times as thick as the interspaces, but actual- 

 ly, excluding the septal ledges, the interspaces are almost twice the 

 thickness of the septa ; towards edge of corallum the shelves are reduced 

 to sharp lines of granules; septa may have additional granules besides 

 the shelves; at the top of each branch of the corallum, the septocostae 

 extend adorally to become faint, granular costae with narrow inter- 

 spaces; basally on corallum, the costae may become lines of granules; 

 septocostae of the lower parts of the corallum meet adoral costae at right 

 angles where the former's identity is lost; columella composed of a 

 single upright plate which is occasionally twisted and contorted. 



Remarks: This species may be distinguished from L. digitata 

 Vaughan by the thicker corallum, the lateral septal ledges, and the 

 smaller columella. It is separated from L. gardineri van der Horst by 

 being only one calice wide, by having fewer definitive septa (in the above 

 description, marginal septocostae are omitted in the septal number be- 

 cause all calices are marginal due to the slender corallum), by the pro- 



