288 BULLETIN OF THE BUREAU OF FISHERIES. 



as one of the most important diagnostic characters of the group, at least so far as distinguishing between 

 species is concerned. 



Polypus californicus appears to be the most common offshore Polypus of the Southern California 

 coast, but no specimens have as yet been taken from a depth less than about loo fathoms. The single 

 abyssal specimen accredited in the above table to Monterey Bay is not only young but has undergone 

 so much contraction that its identity must not be regarded as fully established, and hence the great 

 extension in bathymetric as well as geographic range which it represents may be an error. 



Polypus leioderma Berry, igii. (PI. xx.xv, fig. i; pi. xl, fig. 4-5.) 



Polypus leioderma, Berry 1911, p. 590. 



Body of rather small size; very firm, short, plump, and compact; wider than long, broadest poste» 

 riorly ; truncately rounded. Integument smooth except for a number of short, rather obscure, simple 

 papillae or cirri scattered over the dorsal surface of the head, neck, and anterior part of body; there is 

 one such tubercle over each eye, the remainder likewise showing a bilateral arrangement and widely 

 scattered, the most notable being a nearly equidistant row of four between the eyes, two along the 

 median line just behind, and a number of lateral ones. Bounding the body laterally, and extending from 

 a point just posterior to the mantle margin and above the gill on either side, is a narrow and thin but 

 distinct keel-like fold of the integument, which, though somewhat obscured in places, is still clearly 

 traceable all the way round. There are also a number of deep transverse folds in the nuchal region, 

 but these seem due to contraction and not of a permanent nature. 



Head short, broad, poorly defined by a slight constriction from the wider body. Eyes large and 

 protruding. Funnel long, rather slender, extending well past the base of the arms. 



Arms decidedly unequal, two to three times as long as the body, their order of length i, 2, 3, 4; the 

 dorsal arms decidedly the stouter and longer and the ventral arms the reverse. Umbrella well devel- 

 oped, extending between the first, second, and third arms for over a fourth of their length, and thence 

 continuing along their outer margins to their tips as a very broad prominent contractile membrane; 

 shorter between the third and fourth arms, and even more reduced between the ventral arms where it 

 attains scarcely half its former length, although the webbing to the extremities of the arms is the same. 

 Suckers in two rows, rather small, and relatively very numerous. 



Beak and radula not examined. 



Color over the body a very pale gray-buff, somewhat suffused with a purplish brown; arms and 

 umbrella darker. Chromatophores small and pale in color; of two distinct types, one being larger, 

 sparser, and darker tlian the other. The two largest specimens obtained have the following dimensions: 



Measurements of Polypus leioderma. 



Total length 



Tip of body to base o£ dorsal arms . . 

 Width of body 



Neck 



Head 



Length of funnel 



Dorsal arm 



Second arm 



Third arm 



Ventral arm 



Umbrella between dorsal arms. . 



Umbrella between ventral arms 



Type, catalogue no. 214322, U. S. National Museum; a female (no. 137 of the author's register). 

 Type locality, Shelikof Strait, Alaska, Albatross station 4293, 112-106 fathoms, bottom of blue mud 

 and fine sand ; one specimen. 



