90 RKCKNT MADKEl'ORAKIA OF TIIK HAWAIIAN ISLANDS AND LAYSAN. 



tall, as iiiuch as ;i.5 iiiiii. in dianu'tt-r at tlic base, somewhat appressed, and decreasing 

 in diameter toward th(> apex. C'alices on the verriit-e not ditferent from the others 

 except they are eloser together. The summits of the plates nia^' or may not l)ear 

 verruea'. 



Caliees on the inner portion of the corallum small, o.t! mm. in diameter, on the 

 outer surfaces larger, O.S nun. in diameter. They are distant at least once their 

 diameter, maybe twice, cxceptino- near tlie ends of the branches or on the verruca?; 

 on the veiy tips they are separated l)y v(>ry thin walls. Septa usually distinct, but 

 short, in two complete cycles; all may be of the same length, occasionally more than 

 twelve. Oni^ septum is longer than the otiiers and marks a plane of symmetry. The 

 columella is distinct, terminated by ;i small style, separated by a notch from the 

 elongated septum or directly joined to it. Surface of the coenenchynia minutely 

 and regularly granulate. 



.V second specimen, which 1 am classifying with the one above described, ha.s 

 stubby, more or less comjiressed branches, the summits flattened or verrucose. The 

 widest terminal in this specimen is IH mm. The verrucie grade into lateral branches 

 which, thougii short, are divided into several short ringers. On the outside of the 

 corallum are some rather attenuate ringer-like branches. In form these two speci- 

 mens just overlap. The calices in the second will average slightly smaller than in 

 the rirst. The second specimen in form grades into specimens of P. ce.'<2)it(mi with 

 thickened branches. 



Roth of the specimens above desci'ibed have basal expansions that deserve fur- 

 ther notice. On these the septa and columella are very well developed. The colum- 

 ella is tall and pointed. It is connected with an elongated septum, and frequently 

 there is an enlarged, Init not so prominent, septum on the opposite side of the calice. 

 The well-developed septa and columella give these calices a distinctlj' stylophoroid 

 appearance. 



Localities. — Vicinity of Lavsan Island, Station No. 3959; depth, 10 fathoms; 

 bottom, white sand, coral; temperature at surface, 7S^ F. Cotypes, 2 specimens; 

 U. S. Fish Commission steamer Albatro><i<. Kahana, Oahu, 2 specimens; Pukoo, 

 Molokai, 2 sjiecimens; depth, 3 to 6 feet; W. T. Brigham. 



Coiijjits.—C&i. No. 20S52, U.S.N.M. 



Bet/uirks. — This variety grades into the typical form of the species, into var. 

 tumida and var. hajmnensis. The most characteristic feature of the variety is the 

 wide, compressed branches. The cotypes are further characterized t)y a roughly 

 and rather coarsely echinulate coenenchynia, and strongly developed septa and 

 columella. By varying toward forms with smallei' liranches a passage to typical 

 cenpiUmi is effected; by increasing irregularity in form it intergrades with var. layxa- 

 ne7i.ns; by reduction in the length of its branches it passes into var. tumida. The 

 specimens referr(>d to the variety, but not considered typical of it. show direct 

 passage from calices with strongly developed septa and columella to calices in which 

 those structures are al>sent or only rudimentarv. 



