HYDEOCORALS OF THE NORTH PACIFIC — FISHER 499 



species as Dr. Brocli has done. The uiherent clifTiciilty of allocating an 

 Rimectant species to either Allopora or Stylaster is in no wise lessened 

 when these groups are regarded as subgenera of an expanded Stylaster, 

 although possibly one's sense of responsibility is a trifle lulled. 



These remarks concern a point of view on a matter of usage. They 

 are in no way intended as a criticism of Dr. Broch's truly epoch- 

 making paper. It ranks with Moseley's classic as a standard work 

 absolutely indispensable to future students. 



I am, however, unable to agree ^vith Dr. Broch in the matter of liis 

 new name Eustylaster for the subgenus Stylaster, sonsu stricto. In the 

 subdivision of a genus it seems to me to be axiomatic that the section 

 that mcludes the original type species should retain the original 

 generic designation. 



STYLASTER ELASSOTOMUS, new species 



Plate 41, Figure 3; Plate 42. Figukes 1-lc; Plate 49, Figure 1 



Diagnosis.— Colony small, arborescent, not profuse, branching pre- 

 dominantly in one general plane; cyclosystems resembling those of 

 A. campijleca tylota but with still shorter and very shallow dactylo- 

 tom.es; mouth of the dactylopore at extreme margin of the cyclosys- 

 tem; dactylotom.e very short and shallow (pi. 42, fig. Ih). Type 

 colony 60 mm high, 50 nam broad. 



Description. — The colony is of the Stylaster type. There are no 

 signs of coalescence of neighboring branches. The front of the colony 

 is shown by plate 49, figure 1. The opposite side is devoid of cyclo- 

 S3^stcms, but there are a few male ampullae near the ends of the 

 branches. 



The cyclosystems are notable for the small size of the numerous 

 dactylotomes (10 to 17) and the short distance they encroach verti- 

 cally upon the gastropore wall. The vertical pores are relatively 

 larger than in A. tylota, and the dactylostyle is usually conspicuous, 

 although not always so much so as shown by the figm-e, Vv^hich repre- 

 sents its maximum development. The gastropore is deep and nor- 

 mally curved; style slender, the style chamber differentiated by the 

 presence of slender spicules protruding into its lumen in sharp contrast 

 to the smooth walls of the pore above it. Diameter of cyclosystem 1 

 to 1.2 mm; depth of gastropore about 2 mm; gastrostyle 0.4 to 0.5 mm. 



The m.ale ampullae are scattered on the branches and are not nu- 

 merous. They form low convex blisters, their surface bemg rougher 

 and more porous than that of the surrounding coenosteum. Inner 

 Avail coarsely but not deeply fenestrated. Diameter of interior, which 

 is oblate-spherical, 0.35 to 0.45 mm. Female ampullae not known. 



The coenosteum is compact and hard, but the surface of trunk and 

 base of branches is rougher than m A. tylota, being raised in low 



