Boone, Mollusca, Cruises of "Eagle" and "Ara," 1921-28 183 



the young and whales feed on the larger ones. Man is also their 

 enemy, using them both as food for himself and as bait for com- 

 mercial fishing. W. K. Brooks has given a masterly account of the 

 embryology of this species. A. E. Verrill has reported carefully on 

 the growth rates of L. pealeii. 



Technical description: Squids of six to nine inches. The body 

 is moderately stout, subcylindrical, tapered to a bluntish point pos- 

 teriorly. The length of the caudal fin is equal to three-fifths of that 

 of the body, if the fin is measured from point of insertion to tip. 

 The fins are rounded, long, rhomboidal, their greatest width a little 

 anterior to the middle of their length. The anterior margin of the 

 body is produced to a prominent triangulate point with the tip 

 rounded, on either side of which the margin slopes backward; there 

 are two well-developed, angular points on the ventral margin, one 

 on either side opposite the lateral cartilages. The dorsal connec- 

 tive cartilage is long, tapering posteriorly, with a conspicuous, broad, 

 dorsal keel, the anterior end free, shaped like that of the pen. 



The head is only four-fifths as long as wide, somewhat flattish 

 dorsally, bulging in the dorsal region and excavate ventrally for the 

 reception of the dorsal surface of the siphon, which latter is large, 

 anteriorly rounded, with broad, bilabiate aperture. The lateral car- 

 tilages are long, narrow, subacute anteriorly and posteriorly, in the 

 form of a thin, rounded outer lobe, the median groove narrow. The 

 mantle connective cartilages are simple longitudinal ridges diminish- 

 ing posteriorly. The eye is large. Behind the eye and above the 

 ear, the nuchal crests are situated, consisting of a longer upper and 

 a shorter inferior oblique, longitudinal membranes, these united by a 

 doubly curved V-shaped membrane, with its angle directed forward, 

 the whole approximating a W-shaped design. 



The sessile arms are large, stout, decreasing in size in the order 

 3, 4, 2, 1. All have thin marginal membranes, reinforced by strong, 

 transverse muscle ridges. The first and second arms are trapezoidal 

 basally; the third pair of arms are shorter, compressed and with a 

 median carina on the outer surface. The suckers on all the sessile 

 arms are arranged in two rows, those of the third and second arms 

 respectively being the largest of the series and are very deep, oblique. 

 Toward the distal fourth to fifth of each arm the suckers diminish 

 rapidly in size. The larger suckers have the chitinous ring with the 

 higher outer side divided into six to seven broad flattened subtruncate, 

 blunted, incurved teeth; the inner half of the ring is nearly even. 



