bulletin oe the bureau of fisheries. 
274 
attention, however, is called to the serrated jaws of the forceps themselves, owing to 
the origin of their teeth by interpolation in the way described, and to the periodicity 
thus established, but the biological significance of one set of spines may be as great as 
that of the other. 
VARIATION IN THE POSITION OF THE GREATER FORCEPS. 
As was long ago remarked by Aristotle, a it seemed a matter of chance whether the 
crushing claw were on the right or left side of the body, but this is not altogether the 
case. The large claw occurs about as frequently upon the right side as upon the left, 
without distinction of sex, as shown by the following table, in which 2,433 individuals 
are recorded: 
Table 7. — Showing Variation in Position of Big Claws. 
Sex. 
Crushing 
claw on 
right 
side. 
Crushing 
claw on 
left 
side. 
Claws 
similar 
and of 
toothed 
type. 
Males 
562 
62S 
1 
Females 
602 
638 
2 
Total 
1, 164 
I, 266 
3 
I have shown that in Synalpheus brevicarpus , b of the Bahama Islands, where the 
large hammer claw can be recognized even before the animal is hatched, the members 
of a brood are either right handed or left-handed, that is, have the hammer on the same 
side of the body. This seems to be a case of direct inheritance from the parents, though 
not enough data were collected to settle this point. 
Since the issue of that work my earty observations have been extended by Coutiere 
and our combined results are tabulated below. c 
Table 8. — Showing Position of Big Claws in Broods of Synalpheus. 
No. 
Great 
claws of 
mother. 
Number 
in brood. 
Right- 
handed 
larvae. 
Left 
handed 
larvae. 
d 3 ° 
30 
2 
Left 
4 
3 
2 
1 
5 
Right . . . 
6 
4 
2 I 
6 
Left 
4 
1 
3 1 
7 
. .do 
44 
44 
8 
. . .do 
22 
1 
21 
165 
8 
157 
o ‘In the Carabi and in the Carcini the right claw is invariably the larger and stronger. For it is natural to every animal to 
use its right side in preference to its left. In the Astaci alone it is a matter of chance which claw is the larger, and this in either 
sex.” Aristotle: The parts of animals; translated by W. Ogle, London, 1882. 
b Herrick, F- H.: Alpheus: A study in the development of Crustacea. Memoirs of National Academy of Sciences, vol. 
v. ch. v, 4th mem . p. 370-463 + , pi 1-38). Washington, 1892. 
c Couti&re, H.: Les Alpheidae”, Morphologie exteme et interne; Formes larvaires; Bionomie. Annales des Sciences natu- 
relies. s6r., Zoologie, t. lx, p, i-iv, 1-560, pi 1-6, text fig. Paris, 1899. 
dThe exact number in this brood was uncertain, but all that were preserved were left-handed. No. 1-4 were observed by 
the writer, no. 5-8 by Coutiere. No. 1-3 refer to Synalpheus brevicarpus, no. 4-8 to the smah Synalpheus longicarpus which 
abounds in the big black Hircima sponges along shore. 
