[ 37 ] CEPHALOPODS OF NORTHEASTERN COAST OF AMERICA. 
» 
The ventral arms are trapezoidal in section at base, and rather stout. 
Breadth of front surface, near the base, exclusive of membranes, .55 of an 
inch; transverse diameter, .95 of an inch; front to back, 1.25 inches. The 
sucker-bearing surface is, therefore, broader than in the other arms. 
The suckers are, however, distinctly smaller, and the proximal ones are 
different in form from the corresponding ones on the other arms. They 
are narrower and deeper, with more oblique and more contracted aper¬ 
tures, more oblique horny rims, which are denticulated on the outer mar¬ 
gins only. On the larger ones there are 12 to 15 sharp, incurved denti¬ 
cles. In fact, the proximal suckers on the ventral arms agree better 
with the middle suckers, beyond the 30th, on the other arms, for there 
are none having wide-open apertures, surrounded by nearly even horny 
rims, denticulated all around. The suckers diminish regularly in size, 
and in the number of denticles, till at the 200tli (where the arms are 
broken off) there are but three denticles. 
Young A. Harveyi, No. 24 .—Measurements of arms (in inches). 
Near 
j base. 
At 
5 in. 
At 
10 in. 
At 
15 in. 
At 
20 in. 
DORSAL PAIR* 
.35 
. 50 
. 30 
.20 
. 30 
. 20 
. 75 
. 60 
. 40 
1. 05 
. 90 
. 70 
6ECOND PAIR. 
26. 25 
. 40 
. 50 
. 35 
.22 
.18 
. 25 
. 30 
. 15 
. 80 
. 65 
. 35 
. 30 
. 16 
1. 20 
1. 20 
.85 
.60 
.40 
THIRD PAIR. 
Breadth of front. 
. 50 
. 50 
. 40 
. 20 
. 25 
. 15 
Diameter, transversely. 
1. 10 
. 70 
.40 
1. 08 
1. 60 
1. 20 
FOURTH PAIR. 
Breadth of front. 
. 40 
. 30 
. 20 
. 25 
. 10 
. 98 
. 90 
Diameter, front to back. 
1. 40 
1.12 
TENTACULAR ARMS. 
Total length. 
67 
58.75 
Diameter of slender portion. 
.46 
*' 
Length of club.. 
8. 25 
Length of part occupied by 24 largest suckers. 
4. 25 
Length of part occupied by sinall distal suckers_ 
2. 60 
Greatest breadth of club. 
.70 
Diameter, front to back. 
. 60 
Sessile arms, from base to particular suckers. 
To 
25th. 
To 
50th. 
To 
100th. 
To 
150th. 
To 
200th. 
To 
250th. 
To 
300th. 
To 
tip. ; 
7. 5 
12. 25 
7. 75 
12. 25 
16. 75 
20.25 
22. 90 
24.50 
25.75 
26.25 
7. 25 
12.25 
6.25 
10 
16. 50 
20. 75 
