504 PROCEEDINGS OF THE NATIONAL MUSEU:.! vol.84 



face of main stems; the latter densely beset on back with short thorns. 

 Both surfaces of branchlets crowded with small conical ampullae, but 

 cyclosystems mainly on front and lateral aspects of stems and 

 branches. Cyclosystems spaced 2 to 4 diameters apart on front of 

 colony while on lateral aspect of branchlets they are crowded, often 

 irregular, and sometimes confluent. 



Cyclosystems slightly smaller than in A. campyleca, with usually 

 8 to 12 deep but not very long dactylotomes, fairly conspicuous 

 dactylopores, and small dactylostyles. Gastropore often shallower 

 than in campyleca and frequently not curved (though often set 

 obliquely on the branchlets), so that the slender to moderately robust 

 style can be seen surrounded by a series of dehcate spicules projecting 

 downward from the pore wall (pi. 35, figs, la, Id). These slender 

 spicules are not regularly present in campyleca, wliich thus does not 

 have a sharply differentiated style chamber. Diameter of cyclo- 

 systems 0.75 to 1 mm; depth of gastropore about 0.8 to 1 mm; 

 gastrostyle, 0.4 to 0.5 mm. 



On the lateral faces of the branchlets the cyclosystems are often 

 asymmetrical and broader than on the front. Sometimes two or 

 three cyclosystems merge in such a way that a series of dactylotomes 

 surrounds a depression at the bottom of which are two to four funnel- 

 shaped gastropores (pi. 35, fig. Ic) or two separate styles may occupy 

 the bottom of a gastropore. 



Male ampullae similar to those of campyleca, very numerous, small, 

 conical. The dorsal wall is thin and the cavity is 0.25 to 0.35 mm in 

 diameter, its surface deeply pitted, sometimes rough. Female am- 

 pullae: The only fragment I feel any confidence in assigning to this 

 form has scattered hemispherical ampullae with uneven wall as if the 

 contents had shrunk (pi. 35, fig. 16); diameter, 0.85 mm to 0.9 mm. 



The coenosteum is closely similar to that of campyleca. In less 

 exposed portions the surface becomes rougher and more porous. The 

 main stems of type are very thorny. 



Color, pale buff, usually becoming pale pinkish after cleaning with 

 sodium hypochlorite. 



TV^^e.— U.S.N.M. no. 43266. 



Type locality. — Station 3480, Amukta Pass, Aleutian Islands, lat. 

 62° 06' N., long. 171° 45' W., 283 fathoms, black sand, rocky. 



Specimen examined. — The type and numerous fragments, not all 

 of which are broken from the type colony. 



Remarks. — A. poly orchis comes near to falling in Stylaster, in the 

 vicinity of S. cancellatus, as the cyclosystems are crov/ded in series on 

 the lateral face of the branches so closely as to be frequently con- 

 fluent. But other cyclosystems, generally smaller than these lateral 

 ones, are numerous on the front of the colony, though seldom con- 



