Boone, Annelida, Cruises of "Alva" 93 



has led to the usual establishment of several different species 

 names for it, now accepted as synonyms. These have been dis- 

 cussed by M. Fauvel (1919, also 1932). An excellent discussion 

 of the species, based upon an extensive collection of specimens 

 from various localities, is given by Mr. Crossland (1904), with 

 especial reference to the variable characters. 



The tentacles vary from smooth to faintly annulate. The 

 branchia may begin from the fourth to the twentieth somite and 

 possess from four to sixteen filaments, four to six filaments being 

 the usual number, the branchia continuing to the posterior of the 

 body. The acicula and related setae are dark. The body is nor- 

 mally subcylindrical anteriorly but wide and flatfish posteriorly, 

 the coloration of the body varies from whitish yellow to cocoa or 

 dark chocolate or to reddish brown variably, maculated with white 

 dots; the branchia are usually crimson, the tentacles, parapodia 

 and ventral surface of the body usually creamy yellowish to white. 

 The fourth setigerous somite sometimes but not always bears a 

 distinctive collar of white, sometimes maculated with dark dots. 



Technical description : The following notes were made from 

 the Society Islands specimens, which appear to be the first record 

 of this species from this Archipelago. The body of the preserved 

 specimen is creamy yellowish, faded, without markings ; the ten- 

 tacles, cirri and branchiae are slightly lighter, while the setae are 

 yellowish and black tipped, and the acicules are black. The body 

 is slightly narrowed anteriorly and is also narrowed moderately 

 caudad, but the specimen is unfortunately shrunken by death and 

 the posterior segments are broken off. The total number of seg- 

 ments present is fifty-eight. The length of this specimen, exclu- 

 sive of tentacles, is 43 millimeters, the narrowed anterior width 

 is 4 millimeters, the median width is 6 millimeters and the greatest 

 width is 7 millimeters, all exclusive of the parapodia. 



The praestomium is divided medially in front by a fairly deep, 

 nearly linear vertical incision, each lobe being swollen, subpyri- 

 jform, with the dilated end ectoventrad in position, the lobe being 

 devoid of furrows. In one of these specimens the praestomium 

 is deeply retracted within the peristome. The median tentacle is 

 the longest, being 3.5 millimeters long, or extending to the anterior 

 margin of the second somite. It consists of about 18 thick annuli, 

 each being nearly as long as its related transverse diameter. The 

 tentacle narrows moderately distad to the slender distal portion 



