72 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 43. 



This is the handsomest primnoid in the collection, and shows 

 such marked differences from all other known forms that it forms 

 the type of a very well marked new genus. 



Type-specimen.— Cat. No. S0691,'U.S.NM. ;: .:u.; . / 



Family MURICEID^.^ 



Axis horny, unjointed, not surrounded by a regmar series of water- 

 vascular canals. Calyces various, but never with apertures turned 

 toward branch; a pseudo-operculum present, composed of 8 parts 

 each of which is attached to a tentacle base and is usually com- 

 posed of 3 spicules forming an acute-angled triangle; collaret present, 

 composed of circular rows of spicules; coenehchyma usually bristling 

 with spicules which are of exceedingly varied form. 



Genus ACANTHOGORGIA Gray (emended by Verrill and, 



later, by Nutting.) 



Calyces tubular, their walls with spicules arranged en chevron; 

 margins with a crown of points composed of spicules with a distal 

 thorny point and a proximal mass of tubercles or branched processes, 

 the two parts being separated by a bend in the main shaft of the 

 spicule. 



ACANTHOGORGIA STRIATA Nutting. 



Acanthogorgia striata Nutting, Gorgonacea of the Siboga Expedition, III, The 

 Muriceidse, 1910, p. 20. 



But a fragment of a branch 3.9 cm. long was secured by the U. S. 

 Fisheries steamer Albatross. 



The calyces are rather thickly emplanted on all sides of the branch, 

 in no apparent order. The mdividual calyces are tubular, with a 

 constriction at the distal end, 2.7 mm. high and 1.3 mm. in diameter. 

 The margin is crowned with an indefinite number of sharp thorny 

 points, usually in small bundles of 3 or 4, projecting 1 mm. above the 

 margin. The calyx walls are distinctly striated longitudinally 

 on account of the darker brown mesenteries showing through, and 

 are furnished with 8 longitudinal bands of spicules very distinctly 

 arranged en cJievron. Inside of the crown of points are a number 

 of similar points some of which lie along the dorsal surfaces of the 

 infolded tentacles. 



Spicules: The crown spicules are aU of the regular acanthogorgian 

 type, about 1 mm. long, the distal portion smooth and the proximal 

 part not very abruptly bent and tuberculated. The other spicules 

 are small warty spindles with an occasional tuberculate form. 



Color: The colony is light-brown, and the calyces are longitudinally 

 striated with 8 darker bands. 



I The definitions for the Muriceidse and the genera included in It in the present work are condensed from 

 the definitions given in the author's Monograph on the Muriceidse of the Siboga Expedition, 1910. 



