500 PROCEEDINGS OF THE NATIONAL MUSEUM VOL.84 



vermic Illations in the hollows of which are microscopic pores. On the 

 smoother branches these pores appear as irregular, short sometimes 

 branched slits, indicated in the drawing (pi. 42, fig. Ic). Other pores, 

 about the size of the ordmary dactylopores, are scattered without 

 order over the coenostoum. 



Color of dried colony very pale buff, bleaching to white in hypo- 

 chlorite solution. A second fragment is flushed with pale pink. 



TyjJe.—V.S.^M. no. 43268. 



Type locality. — Station 4781, off Agattu Island, Aleutian Islands, 

 lat. 52° 14' 30" N., long. 174° 13' E., 482 fathoms, fine gray sand, 

 pebbles; bottom temperature 38.6° F. 



Specimens examined. — The type colony and a fragment 50 mm long. 



Remarks. — The structure of the colony resembles that of a specimen 

 of Stylaster profundiporus Broch from Sagami Bay, Japan, but the 

 likeness ends there. In profundiporus the dactylotomes are radially 

 as long as the width of gastropore, wliich does not flare, trimipetlike, 

 at the mouth. The dactylotomes cut deep in the wall of gastropore, 

 and the intervening ridges between the dactylotomes are prominently 

 decurrent on the sides of gastropore, as in Allopora campyleca trachy- 

 stoma. 



STYLASTER GEMMASCENS ALASKAN US, new subspecies 



Plate 47; Plate 48; Plate 54, Figure 2 



Diagnosis. — Diftering from S. gemmascens (Esper) ^ of the north 

 Atlantic in the form of the prominent ampullae, which have an uneven 

 rugose surface as if the wall were shrunk; and in the sm-face of coenos- 

 teum, which is thorny or traversed by fine ridges, sometimes decurrent 

 from rim of cyclosystems. Colony flattened with a definite front and 

 back, the majority of cyclosystems being on sides of branchlets, often 

 at an angle so that the inner dactylotomes are destroyed or suppressed. 



Description. — The characteristic form and posture of the cyclosys- 

 tems are indicated by the figures (pis. 47, 48). The gastropore is 

 usually funnel-shaped, broad at top, very narrow at bottom. There is 

 a differentiated style chamber the top of wliich is marked by tiny 

 spicules at about midheight of the slender spiculate gastrostyle. 

 The upper flaring chamber of gastropore is about as deep as width of 

 cyclosystem, or a little less. On the outside of the calyxlike cyclo- 

 systems are delicate decurrent ridges like the costae of madreporarian 

 corals. These correspond to the septa between the dactylotomes. 



The cyclosystems are usually asymmetrical in various ways. The 

 greatest diameter measures 1 to 2 mm. Dactylopores 10 to 18, 

 usually about 12; dactylotomes cut rather deep on sides of gastropore; 

 gastrostyle very delicate, slender, inconspicuous, less than half as 

 long as the gastropore axis. 



• Broch, 1914. p. 8, pi. 1, figs. 4-7; pi. 2, fig. 16; pi. 3, figs. 21, 30; pi. 4, figs. 32, 33. 



