CEPHALOPODS OF THE PHILIPPINE ISLANDS 141 



enormous. The eyelids are triangular with rounded corners, truncate 

 posteriorly, and tapered anteriorly with a distinct small sinus in the 

 anterior border. 



The arms are long, especially so in the larger specimens in the order 

 4.2.3.1, IV attaining as much as 90 percent of the mantle length. 

 The arms are squarish in cross-section, rounded aborally, and flat- 

 tened both orally and laterally. Arm III is keeled along most of its 

 length. The suckers are biserial and bordered on either side by a 

 narrow trabeculate protective membrane; they are small, round, and 

 laterally inserted, rather crowded. On III and IV, the basal five or 

 six suckers are in a single row, the others biserial. Near the base of 

 the arms, the sucker rings are nearly smooth, with about seven low 

 square teeth. At the 7th row there is a single slender median tooth 

 and several blunt laterals; at the 11th row there are eight or nine teeth 

 of which several are slender and square cut. These may be compared 

 with Sasaki's illustrations of suckers from the same positions. All the 

 suckers are bordered by a narrow papillated ring which becomes 

 pointed on the distal margin. 



The tentacles are long and slender, romid in cross-sections and 

 narrower than the arms. The club is little expanded and is 38.3 

 percent of the mantle length and about half the length of the tentacle. 

 The tentacular suckers are very small and numerous and appear to 

 form about 20 rows across the midpart of the club. The suckers are 

 slightly oval, somewhat pointed distally and have the horny ring 

 armed with teeth all around the circumference. The teeth are 

 slender and square tipped, short proximally, but long and slender 

 distally. The ring is surrounded by a band which bears large papillae 

 in several rows. 



The color, in alcohol, is yellowish, but the body is liberally covered 

 with small reddish-brown chromatophores. 



The gladius was not examined. 



Measurements and indices of six specimens of Mastigoteuthis 

 cordiformis Chun, 1908, are: 



