264 A. E. Yerrill — North American Gephalopods. 



suckers diminish regularly in size, and in the number of denticles, 

 till at the 200th (whei'e the arms are broken off) there are biit three 

 denticles. 



! 

 Tentacular-arms. 



Plate XXVI, fig. 2. 



The tentacular-arms are both entire, with all the suckers well pre- 

 served. The total length is 65 and 67 inches respectively ; length of 

 the expanded portion or club, 8*25 inches; diameter of the peduncu- 

 lar portion varies from '40 to '70 of an inch ; at the base, '90 ; breadth 

 of the proximal part of the club, where it is broadest, '70 ; diameter 

 from front to back, '60; external diameter of the largest suckers, 

 "6b of an inch; height of their cups, '28; of lateral suckers, 'IS; of 

 the largest marginal suckers on the distal portion, "14. 



The peduncular portion is somewhat thickened and rounded at the 

 base, but through most of its length it is slender, varying in size, and 

 nearly triangular in section, with the corners rounded, each side 

 measuring, where largest, '60 of an inch in breadth. At about a foot 

 from the base the small smooth-rimmed suckers and their opposing 

 tubercles begin to appear on the inner surface. At first these are 

 placed singly and at considerable intervals (2*5 to 3*5 inches), each 

 sucker alternating with a tubercle on each arm ; further out they 

 are nearer together, and towards the club they alternate, two by two, 

 on each arm ; near the commencement of the club they become more 

 numerous and ai'e arranged somewhat in two rows ; just at the 

 commencement of the club they become more crowded, forming 

 three and then four oblique transverse rows of suckers, with the same 

 number of tubercles alongside of them ; on the basal expansion 

 of the club, which is its thickest portion, these suckers and tubercles 

 become very numerous, covering nearly the whole inner surface, form- 

 ino- rather crowded and irregular oblique rows of six or more. These 

 smooth-rimmed suckers are followed by an irregular group of about 

 twenty, somewhat larger, denticulated suckers, occupying the entire 

 breadth for a very short distance. Then follow the two median 

 rows of large suckers, alternating with a row of marginal ones, of 

 about half their size, on each side. The first three or four large 

 suckers of each row gradually increase in size ; then follow six to 

 eight nearly equal ones of the largest size ; these are followed by 

 two to four distal ones, decreasing in size. In one of the rows there 

 are fourteen that distinctly belong to the large series ; in the other 

 row there are twelve. The distal section of the club is occupied by 



