NO. 1923. DESCRIPTIONS OF PACIFIC ALCYONABIA— NUTTING. 81 



ACIS SQUAMATA Nutting. 

 Ads squamata Nutting, Muriceidse of the Siboga Expedition, 1910, p. 42. 



Colony flabellate, very profusely branched, 6.2 cm. long and with a 

 spread of 5.2 cm. The base is lacking, the part preserved consisting 

 of two main branches which anastomose distally, their basal parts 

 being free. The larger branches are three in number, sending off 

 numerous side branches some of which again divide until branches of 

 the fourth order are produced. Side branches very closely approxi- 

 mated, often not more than 1 mm. apart. The calyces are all anterior 

 or antero-lateral, mostly the latter, close set, less than 1 mm. apart 

 and often contiguous. 



The individual calyces are variable in shape, being low verrucas, 

 short tubes, or truncated cones. A typical one measures 1.7 mm. in 

 height and 2 mm. in diameter. Their walls are armed with large 

 squarish plates often in two, sometimes in three, series. The trans- 

 verse diameter of these plates is usually longer than the vertical, and 

 their free edges are thin and finely ctenate, the other edges being fitted 

 together forming a complete covering. The free edges are usually 

 Tounded. The distal row looks like an operculum composed of a 

 flattened scale for each tentacle, but dissection shows that the true 

 operculum is under these and is composed of two comparatively 

 slender spindles lying longitudinally along the dorsal surfaces of the 

 tentacles. The coenenchyma is covered with squarish or polygonal 

 plates, their edges nicely fitted. Those on the anterior surface of the 

 colony are much larger than the others, sometimes reaching a length 

 of 4 mm. Those on the back of the colony are small, squarish or 

 polygonal plates averaging not more than 1 mm. in diameter. 



The spicules have already been described. They are the heaviest 

 that the writer has seen in the Gorgonacea. 



Color: The axis is dark brown, and the polyps are dark umber- 

 brown with a slight purplish tinge. The general surface is white, but 

 the dusky color of the axis and polyps shows through somewhat, 

 imparting a slightly bluish tinge. 



Locality.— Station 4936; Sata Misaki Light, N. 21° E., 5.7 mUes; 

 103 fathoms. 



The type-locality is Dutch East Indies, near Saleyer Island, 400 

 meters. 



The U. S. Fisheries steamer Albatross specimens agree with the 

 type except in the color of axis and polyps, which, in the type, are 

 much lighter. This may be due partly to the fact that the Siboga 

 material has been longer preserved in alcohol than that secured by 

 the Albatross. 



48702°— Proc.N.M.vol.43— 12 6 



