BULLETIX 5y, UNITED STATES NATIONAL MUSEUM. 87 



They are numeroii.s and crowded. Speriinon No. t'.sl (one of Dana's originals, which 

 bore tile name /'. (Intiiiiuiriiix '.) has the ends of tlie main steins not so profusely 

 branched, and the suniniit branehlets more distant, .shortei", and thicker. Specimen 

 No. 2186 has still thicker branches, and their ternunals are sometimes swollen. Two 

 specimens, No. 72*2 (one of Dana's specimens) and No. 218H, are figured to show this 

 variation, Plate X, figs. 1, la, 2, 2a/ the intermediate specimens are not figured. 



The calices are rather large, about 1 nuu. in diameter; they may be a small frac- 

 tion more or less. They are with rare exceptions crowded, the walls between them 

 being less than their diametei-. The septa are only poorly developed or may be 

 obsolete; the columella is a low, elongated or roundc^d, granulatiid dome. A number 

 of the calices show distinct bilaterality, as the septa at theii' ojjposite ends are more 

 developed and connect in the bottom with the columella. The surface of the 

 coenenchyma is covered with small, pointed granulations. 



Two of the specimens collected liy the AlhutrosK expedition of 1902 are figured, 

 Plate XI, tigs. 1, 2. The calices of these specimens average smaller than in the type 

 material, and the septa in the calices near the ends of the ))ranches are somewhat 

 more developed. 



Localities. — Reef at Honolulu, 1 small, young specimen; reef at Kaunakakai, 

 Molokai Island, 4 specimens; Hawaiian Islands, no definite locality, 2 small young 

 specimens; collection U. S. Fish Commission steamer Alhoffoxx, Hawaiian Islands. 

 No definite locality, it specimens; United States National Museum collections. Kahana, 

 Oahu, 8 specimens; Pukoo, Molokai, 2 specimens, depth 3 to (5 feet; W. T. Erigham. 

 Pukoo, Molokai, and Waikiki, Oahu, J. E. Duerden, collector. Laysan, Studer. 



Reiiuirlx. — Variation is ak)ng five directions: 



1. Form. Branehlets, elongate and slender to stumpy with swollen ends; from 

 terete to compressed and frondose. The upper surface of the corallum may l>e 

 neatly rounded, or the branches niaj' be divergent and straggly. 



2. Verrucas They are absent on the deJicately lu'anched forms, and may or 

 may not be absent on tne frondose varieties. 



3. Ornamentation of the coenenchymal surface. From subglabrous. with minute 

 spinules to coarsely spinulose. 



i. Distinctness of septa. From ol)solete to comparati\ely well developed. 



."). Distinctness of columella. From entirely absent to stylophoroid. 



In discussing what is considered tj'pical /'. ccspitom, it has already been stated 

 that for the typical form some latitude is allowed in the variation of the attenuatenfess 

 of the l)ranchlets and the comparative development of the septa and coluuKdla. The 

 surface granulations of the coTiencliyma vary considerably in l)oth prominence and 

 size. The three varieties recognized are especially characterized as follows: 



P. cespitosa var. tumidu has short branches with swollen ends. 



P. cespitoxa var. laymiUHsin has spreading, straggly, terete or compressed 

 branehlets; when the branehlets are compressed, verructe are almost entirely absent. 

 Ccenenchymal graiudations rather coarse. Septa and columella may l)e distinct. 



I', ccxpi/o'oi Viiv. Kfi///i/j/ifiri>/i/, II has frondose l)ranclies, with irregularly developed 

 verrucsw. Coenenchymal granulations coarse. Septa and columella usually --trongly 

 developed. 



