102 U.S. NATIONAL MUSEUM BULLETIN 234 



either side on I-III by a protective membrane of which the ventral 

 part is deepest. IV has very low, rudimentary membranes but bears 

 a well-developed swimming membrane on its dorsal surface. 



The tentacles are long and slender, shghtly flattened, about 100 

 percent of the mantle length, with a small, slightly expanded club. 

 On the hand part of the club is a series of three or fom- long slender 

 curved hooks. These may be 3-3, 3-4, or 4-3 but are usually 4-3, 

 with four hooks on the right club and three on the left. The sizes of 

 the hooks vary greatly. The proximal one may be very minute or 

 nearly as large as the second or aU may be approximately the same 

 size. The variableness does not seem to be related to the size of the 

 animal. Dorsal to the hooks are two irregular rows of suckers. 

 Distal of the hand are four rows of small suckers. The suckers are 

 bordered on either side by a protective membrane. Ventrally, this 

 membrane originates at the middle of the carpal connectives and is 

 at first broad and somewhat semicircular, but at the base of the second 

 or third hook it becomes low and extends to the distal end. Dorsally 

 the membrane originates more distally and is low throughout, although 

 somewhat broader basally. On the outer surface of the club is a 

 broad swimming membrane. The carpal cluster consists in almost 

 all specimens of fom* small cups and four knobs or buttons. 



In the male the left ventral arm is hectocotylized. In a specimen 

 of 32.0 mm. ML from Sta. D5116 there are 13 hooks on the right 

 ventral arm, 7 in the dorsal row and 6 in the ventral row; the arm 

 ends with about 10 small suckers succeeded by a series of minute 

 suckers extending to the tip. However, on the left ventral arm there 

 are 11 hooks consisting of 5 dorsally and 6 ventraUy. Distad of these, 

 the arm is devoid of suckers with the oral siu-face smooth. On the 

 ventral side, originating at the base of next to the last hook is a wide, 

 somewhat circular flap which distaUy becomes low and extends to the 

 tip of the arm. It slightly curls over the oral surface of the arm. 

 On the dorsal surface the protective membrane continues as a low 

 web to beyond the terminal hook where it suddenly and abruptly 

 widens into a semicircular flap which curls over the arm distal of the 

 ventral flap. Distally it narrows and extends to the tip. 



The light organs, as in all Abralia, are numerous and conspicuous, 

 characteristically arranged, and of the three usual types. Most 

 diagnostic of the present species is their arrangement upon the ventral 

 periphery of the eyebaU. These are five in number, the anterior and 

 posterior photophores large and conspicuous, the anterior one oval, 

 shghtly less than one-half the size of the posterior one and with both 

 a dorsal and ventral sinus. The posterior one is large, oval, pointed 

 posteriorly, occasionally with traces of a sinus dorsaUy. Between 



