420 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [210] 



narrowing abruptly anteriorly; the anterior lobes are small, rounded, 

 and project only slightly forward beyond the insertions. Siphon large, 

 with a well-formed valve, far back from the orifice ; dorsal bridles rudi- 

 mentary. Connective cartilages on the base of the siphon, broad-ovate, 

 ear-shaped, with two rounded prominent lobes projecting into its con- 

 cavity, one posterior, the other ventral, so that the pit is three-cornered 

 (fig. lb). The corresponding connective cartilages of the mantle consist 

 of two pits, separated by a prominent, triangular tubercle (fig. If). 

 Head large, in proportion to the body, tapering backward from the bases 

 of the arms. Eye& large ; lids thin and simple, without a distinct lach- 

 rymal sinus. Behind and below each eye is a long (4 mm ), slender, clav- 

 ate papilla (fig. 1/), probably olfactory in function. 



The sessile arms are large and, except the ventral, unusually round- 

 ed; the inner or sucker-bearing faces are much less differentiated than 

 usual, scarcely differing from the other sides in color, and bordered by 

 only a slight or rudimentary membrane on each side; the rounded prom- 

 inences from which the sucker-pedicels arise are also colored and not 

 much raised. The dorsal arms are rather long and tapering, but much 

 shorter and smaller than the others, slightly compressed, and with a 

 slight median crest distally. The next pair are similar in form and 

 structure, but considerably longer and larger. The third pair are much 

 longer and larger, with the outer angles well rounded, and a strong me- 

 dian crest extends nearly to the base, but is wider distally, where the 

 arms are strongly compressed. The ventral arms are considerably 

 longer and stouter than the third pair, and very different from all the 

 others in form ; they are strongly compressed in the direction parallel 

 with the median plane of the head, and have the lower and outer angles 

 well rounded, and the sucker-bearing face wide and scarcely differenti- 

 ated from the lateral faces; but on the superior lateral side there is a 

 wide and thick crest running the whole length of the arms, giving them 

 a strongly and obliquely compressed appearance. The suckers on the 

 ventral arms are smaller, fewer, and more distant than on any of the 

 others ; those at the bases are largest and three or four stand nearly in 

 a single row; farther out, along the middle of the arm, they are dis- 

 tantly arranged in two rows and rapidly become small. The left ventral 

 arm shows no signs of being hectocotylized ; the right one, however, 

 has lost half its length by mutilation. On all the other arms the suck 

 ers are regularly and much more closely arranged in two rows, and de- 

 crease more gradually in size from near the base to the tips. 



The suckers on all the arms are similar in form; they are rather deep, 

 narrowed at the rim, slightly constricted above the middle, and swollen 

 below, and very oblique at the base; the pedicels are slender and nearly 

 laterally attached; the horny rings are very deep and oblique, and 

 strongly denticulated on the outer or higher side, but on all the arms 

 they are smooth on the inner side; the median, outer denticles are long, 

 slender, close together ; laterally they become shorter, broader, acute- 



