272 
BUI^LETIN OF THE BUREAU OF FISHERIES. 
cracker, as in this case, and in giants the difference is sometimes striking. The dry shell 
of this crusher is so dense and strong that it will bear the weight of a man of average 
size without giving way. The measurements of these claws are as follows : 
Crushing claw: 
Length propodus 
Greatest breadth 
Greatest girth 
Contents 
Weight of shell (8% oz.) . 
Toothed forceps: 
Length propodus 
Greatest breadth 
Greatest girth 
Contents 
Weight of shell (4}^ oz.) 
inches. . 
do ... . 
do. . . . 
.cubic centimeters. . 
grams. . 
inches. . 
do ... . 
do ... . 
. cubic centimeters . . 
grams. . 
8^ 
4l^ 
iiVa 
680 
235 
8^ 
33 ^ 
8^ 
320 
116 
The armature of this cracker claw (fig. 2 and 3 , pi. xlih) is typical and does not 
essentially differ from that found in giant lobsters weighing upward of 25 pounds. 
showing origin of “molars” by fusion of spines. The proximal tubercle of the propodus (L)) is de- 
rived from the lock spine, while the distal (d) is composed of a fused mass of over a dozen teeth, embrac- 
ing the whole of period n, and part of ni. Length of claw 14.5 mm. 
As in their case also the blunted end of the dactyl meets the big distal “molar” of 
the propodus, which, in the Belfast lobster, is worn flat and is inches long by 
inches broad. The dactyl in the slenderer claw is considerably longer, and as 
noticed above in mammoth lobsters the toothed forceps tends to surpass the crusher in 
length. 
Since writing the preceding paragraph I have had the opportunity of reexamining 
the New Jersey lobster, which holds the record for size and weight (see no. 9, table i), 
and find that the great claws which here reach the extreme known development of 
such organs, conform to the types already described and to conditions met with in mam- 
