HYDPvOCORALS OF THE NORTH PACIFIC — FISHER 511 



often delicate and subdividing freely. There is a definite front and 

 back, the protuberant cyclosystems being rather widely spaced on 

 former, very few on latter. They are more numerous on the lateral 

 faces of the branches, but when these are not compressed the cups are 

 scattered on all surfaces. The smallest cyclosystems near end of 

 branchlets have 9 or 10 dactylotomes; the full-sized systems, 12 to 18. 

 The most trenchant characteristics of the c3^closystem are the deep 

 and narrow dactylotomes and the spongy radial septa, which extend 

 over the gastrostom.e and continue downward toward the stjde cham- 

 ber as ridges on the wall of gastropore. As a result the gastrostome is 

 conspicuously narrower than the pore below the level of the dactyl- 

 otomes, as may be seen in a section view (pi. 54, fig. 1). The dactylo- 

 tomes are deep, the slit descending conspicuously upon the wall of 

 the gastropore. Diameter of full-sized cyclosystem 1 to 1.4 mm; 

 depth of gastropore 2 to 3 mm; gastrostyle, 0.5 mm. 



The peripheral branchlets are more or less flattened and on their 

 sides the cyclosystems are usually asymmetrical, the distal dactylo- 

 tomes being longer than the proximal (pi. 54, fig. 16). There are also 

 short flattened spinous outgrowths, especially on the lateral margin, 

 or ambitus, of the branches, entirely independent of cyclosystems or 

 ampullae (pi. 46, fig. 2). Cyclosystems are very scarce on the back 

 of the colony. In several places branches have been broken off and 

 new ones have grown from the truncated end. 



Male ampullae small, as in campyleca, rather closely and irregularly 

 scattered on the front and back of branches ; their convex dorsal wall 

 about half as thick as the diameter of the subspherical interior (which 

 is 0.32 to 0.42 mm). Female ampullae resemble those of campyleca in 

 form, but the surface is minutely roughened, or provided with small 

 tubercles, or on peripheral parts of colony may be traversed by low, 

 narrow, interrupted ridges (pi. 54, fig. la) giving a rugose appearance. 

 The inner surface is pitted but is not particularly spongy or spiculate. 



Coenosteum very hard; the surface not shiny but minutely rough- 

 ened and porous; the texture accentuated on the septa of the cyclo- 

 systems and on surface of ampullae. The tiny vermiculations or 

 interrupted irregular ridges to which the surface texture is due are 

 beset with microscopic spicules similar to those of brochi. 



Type.— \J. S.N. M. no. 43265. 



Type locality. — Station 4784, off East Cape, Attn Island, Aleutian 

 Islands, lat. 52° 55' 40" N., long. 173° 26' E., 135 fathoms, coarse 

 pebbles. 



Specimens examined. — Parts of two female colonies and of two male 

 colonies. 



