740 : General Notes. 
hatching. Such is not the case, since the thin distinct inner mem- 
brane ruptured at the time of hatching is not a molted larval 
skin, but an egg-membrane which was developed within the ovary. 
This egg-membrane is invested at the time of oviposition by a 
much thicker coating of a viscid substance, which is continued 
into the flexible threads by which the eggs adhere together in 
clusters and are suspended to the setæ which fringe the abdom- 
inal appendages of the adult female. At the time of hatching the 
young hang for a short time more or less firmly to this inner 
membrane, grasping it with the rostral spine and telson, 
The first stage.—This stage is the one which the young lobsters 
present at the time of hatching. They are essentially Schizopods 
during this and the succeeding three stages. During this stage 
the young have no abdominal appendages, and swim about as 
pelagic larve by the help of the outer rami or exopodites of the 
ce six hinder cephalothoracic pairs of appendages; the endopodites 
or inner rami of the six hinder cephalothoracic appendages are 
: not used in locomotion during this stage, and are almost wholly 
subservient to the purpose of prehension. The telson is a single, 
_ very broad, somewhat triangular piece, with strong spines at either 
| posterior angle. The total length of the larva at this stage is : 
i eight millimeters. 
: Second stage—This stage follows the preceding abruptly m 
‘Upon its accomplishment the larva has increased 1.5™™ in length, 
as the young lobster is now 9.5™™ long. The second to the fifth 
abdominal somites have also acquired appendages. 
_ Third stage —This follows the preceding, and is preceded by a 
-second ecdysis about the tenth to the fifteenth day after hatching. 
-The penultimate or sixth abdominal segment also acquires a pal 
of biramous, lamellar appendages, which fold alongside of and 1 re- 
Fraea the telson. The young animal now measures II.5 in 
- Fourth stage-—This one succeeds the preceding, and is preceded 
by a third ecdysis on the fourteenth to the eighteenth day a 
hatching. The young lobster differs but little, except 1m s1z° an 
_ the proportional strength of the successive pairs of appende 
from the foregoing stage, and now measures 13™™ in length. Rees 
and the preceding stage was apparently confounded by Pro ae 
S. I. Smith,’ who seems to regard the two as representing bu 
igle phase of development. E 
Fifth stage—This phase of development of the lobster gess 
« 
3 
abruptly into a type very closely resembling the adults, 
the first and third stages. 
[August, 
forms the young creature at the end of about the third wee wy 
me 
: 1 The Metamorphoses of the Lobster and other Crustacea. Report of ey a plate 
nission, Part 1, 1871 and 1872, pp. 522-537, pl. 1x. (Figs. 38 an4 39 © 6 
Teport represent very accurately t ) 
