182 
BULLETIN OP THE UNITED STATES FISH COMMISSION. 
Tlie following measurements show the proportions of some of the parts : 
Measurements. 
Millime- 
ters. 
Length, June 27, 1894 
36 
Length of carapace 
16.5 
Greatest breadth of carapace 
7.9 
Length of antennary flagellum. 
33 
Length of right chela (propodus) 
13.5 
Greatest breadth of chela 
4 
Length of dactyl 
7 
Measurements. 
Millime- 
ters. 
Length of left chela (propodus) 
13 
Greatest breadth of chela (propodus) . . 
3.6 
Length of dactyl ... 
7.8 
Length of telson 
5 
Breadth of telson at base 
4.1 
Length of fringing setae 
2 
Diameter of cornea of lateral eye 
2 
This lobster was kept in a small glass aquarium, and fed with clams and with 
lobster and cod eggs. It was undoubtedly undersized for its age, having molted about 
fifteen times. 
The three lobsters raised in 18S6, which on December 10 measured 35,30.3, and 
51.8 mm., respectively (Nos. 7, 8, 9, table 35), had probably molted twelve times in the 
first two instances and fifteen times in the last. 
Lobster No. 10 (table 35).— When this young lobster was brought up accidentally 
on a lobster pot in Woods Hole Harbor July 18, 1891, it measured only 47 mm. (See 
colored drawing, plate 26.) If it was hatched in the summer season it must have 
been a little over a year old, and it is very probable that in this case also there had 
been fifteen molts. 
The youngest lobsters taken in Casco Bay, Maine, October, 1893 (Nos. 1, 2, table 
32), were doubtless hatched in the previous June, and were therefore about 10 weeks 
old. They had probably passed from thirteen to fourteen molts. 
It is, therefore, clear that the young lobster varies very considerably in its rate of 
growth, whether under artificial or natural conditions. In a state of nature the young- 
lobsters hatched in June are probably from 2 to 3 inches long when 1 year old. (See 
pp. 96-99.) 
I will now add a tabular statement of the successive molts of the adolescent lob- 
sters, whose development has just been considered. Further details of their history 
are given in table 34. 
Table 35 . — Successive molts of young lobsters and their measurements in millimeters. 
No. of lobster. 
Number of molt. 
Date of 
last 
measure- 
ment. 
Age in 
days. 
i 
2 
3 
4 
5 
6 
7 
8 
9 
10 
n 
12 
13 
14 
15 
13 
14. 2 
18.4 
01 9 
107 
2 (No 4 table 24) . 
1G. 5 
19. 5 
22.6 
Aug. 14 
79 
11 
1 12. 5 
13. 4 
15 
2 17. 05 
19. 75 
105 
J (No 24 table 34) 
1G. 3 
18 
21 
2 25 
29. 5 
94 
5 (No 39 table 34) 
24 
28 
Aug. 13 
80 
18.5 
21 . 2 
25 
2G. G 
294 
7 (No 17 table 23) - 
2 35 
2 173 
2 36. 3 
...do 
2173 
9 (No 19 table 23). 
2 51.8 
...do .... 
2 173 
10 (No 22, table 23). 
2 47 
July 18 
2 390 
1 I 
1 Approximate. 2 Number of molts, length, or age estimated. 
THE MOLTING OF THE EMBRYO AND LARVA. 
The first euticular structure formed in the egg is a delicate blastodermic mem- 
brane, which appears in the later stages of yolk segmentation and has often been 
erroneously considered to belong primarily to the ovum. It becomes so firmly glued 
