122 LiULLETIX OF THE 



the arms aro, l)ut little elevated, and have very broad bases ; they alternate regu- 

 larly, anil tliL'ir borders nve nearly or (juite in contact. Tlie three suckers next 

 the mouth on each arm are nearly in one line ; the smaller inner ones I'orming 

 a re!,'ular circle ai-ound the mouth. 



In the male, the Yvj]it arm of tlie tliinl pair is hectocotylized. This arm is 

 decidedly shorter than its mate, antl tapers much more rapidly to the tip, which 

 is acute ; alonj,' the posterior dorsal angle of the arm there is a strong, broad 

 membranous fold, with the lower surface strongly concave, white, and crossed 

 by numerous distinct transverse grooves ; the outer edge of the membrane is 

 tliin, sharp, white, and curves inward over the groove. The groove with its 

 covering membrane extends close to the tip of the arm, where it terminates in a 

 minute conical papilla ; beyond this, there is a minute, conical, naked tip, but 

 without any appearance of the spoon-shaped ca\'ity and transverse grooves 

 found in other species of Octopus. 



In alcoholic specimens the entire upper surface is usually very dark purplish 

 brown, varying to dark bluish gray. In some specimens there are obscure 

 patches of darker and lighter over the upper surftu-e. In all the specimens 

 examined there is a large, rounded, purplish black spot near tlie base of the 

 web, and corresponding to the interval between the second and third pairs of 

 arms. Lower surface of the body, head, and web much lighter than the upper 

 surface, dull grayish or yellowish white, finely specked with purplish chro- 

 matophores. Terminal portion of the siphon darker, much like the dorsal sur- 

 face, inner surface of the wclj and arms grayish purple,' paler than the upper 

 surface. Inner surface and rim of the suckers yellowish white. 



The largest male observed (from San Diego, Cal.) has the dorsal arms 325 

 and 390 mm. long, from the mouth ; second pair of arms, 540 and 450 mm. 

 long; third pair of arms on left side, 550 mm.; right (hectocotylized) arm, 

 400 mm. ; ventral arms, 500 and 490 mm.; greatest transverse diameter of the 

 dor.sal arms, 20 nun.; lateral arms, 25 mm.; ventral arms, 20 nun.; diameter 

 of the larger suckers of the lateral arms, 11 to 14 mm.; of the twelfth sucker, 

 15 to l(i mm,; breadth of the web between dorsal arms, from the mouth, 

 GO mm.; between lateral arms, 70 to 100 mm.; between ventral arms, 60 mm.; 

 length of body, 70 mm.; greatest breadth, 75 mm.; vertical thickness, 42 mm.; 

 breadth of head across eyes, 45 mm.; breadth of dark spot at base of web, 

 20 mm. 



A somewhat smaller male, witli the tissues more contracted, has the dorsal 

 arms 205 mm. long ; second pair of arms, 270 mm. (probably reproduced) and 

 280 mm. ; third pair of arms, 300 mm. (left siilc) ; hectocotylized arm, 265 nnn. ; 

 ventral arms, 285 mm.; diameter of the twelfth sucker of the lateral arms. 20 

 to 22 mm.; of the adjacent suckers, 12 to 14 nun.; length of body, 70 mm.; 

 breadth, GO mm,; breadth of head, 45 mm. 



This species has an extensive southern distribution on the Pacilic const. It 

 is common at San Diego, California, where it has been tibtained liy Dr. Edward 

 Palmer and others. Numerous small specimens were oljtained at Panama and 

 on the coast of San Salvador by ^\v. Frank II. Bradley, ibr the IMuscum of 



