166 Bulletin, Vanderbilt Marine Museum, Vol. IV 



are almost right angled. The siphon is large. The head is slightly 

 longer than wide, decidedly narrowed into a neck posteriorly, bearing 

 dorsolaterally eight slender, longitudinal cartilages of unequal sizes; 

 the more dorsal ones are very small, increasing in size from one to 

 seven, the eighth being equally as large, but only half as long as the 

 seventh. The mantle margin around the eye is produced at the lower 

 anterior angle into a forward projecting curved point. The eye is 

 large; the ventral surface of the head flattish anteriorly and is much 

 excavated posteriorly beneath the siphon. There are two ventral 

 longitudinal neck cartilages on each side, one on the margin and a 

 much thicker one adjacent one on the outer side. The sessile arms 

 decrease in length in the order 4, 3, 2, 1; there being but little 

 differences in the lengths of 4, 3, and 2, while 1 are only a little more 

 than half as long as 2. The second pair has a slight web on its outer 

 margin ; the third pair has this web accentuated ; on the fourth pair 

 the web is on the upper lateral margin. The suckers are in two longi- 

 tudinal rows, and are of moderate size, rounded, set obliquely, with 

 an odd rounded, ear-like process set on the anterior margin of each 

 sucker. The horny ring is smooth. Transverse muscle prominences 

 occur on the ventral face of the arm between each sucker and the 

 next one. The tentacular arms are very extensile, as long as, or a 

 little longer than the body, with a distinct keel along the outer 

 lateral margin, which along the club becomes wider, forming a web. 

 The club is about one-fourth of the total arm length, armed basally 

 with a pad of ten or twelve small suckers and a double row of curved 

 hooks, the outer or ventral row of which are the larger hooks, of 

 which there are eleven; the smaller row has twelve hooks. About 

 midway the club, four or five of the hooks are greatly enlarged, these 

 each have basally a rounded or sucker-like opening. The hooks dimin- 

 ish in size toward the tip of the club. The very tip of the arm has 

 eleven or twelve small, round, short-set suckers, the horny rings of 

 each being smooth. These suckers form a pad-like cluster. The hooks 

 are gloved in a thick skin. The pen is dark brownish, lanceolate- 

 pinnate with a short shaft, anteriorly pointed; the wings are thin 

 with rounded outer margin. 



References: Loligo banksii Leach, Zool. Misc. The Class Cephalo- 

 poda, vol. Ill, p. 141, 1817, London; Tuckey's River Zaire, 

 Appendix IV, p. 411, 1818, London. 



Onychoteuthis banksii Ferrusac and D'Orbigny, Cephal. Acetab., 

 p. 330, 1839.— Pfeffer, Die Cephal. der Plankton Exped., p. 70, 



