84 Part L11.—Twenty-third Annual Report 
. Special Characters of 
gs pee F Beoilting Form. 
IIla. ays Pleopeds and Telson of Megalops. 
Ila. =¢ Ns 
Ila. Megalops. Short Antenne. 
IIIb. EV | Pleopods of Megalors. 
I1Td. Megalops. 
ITTd. . 
ITTd. _ 
ITTd. “a 
el ig In some respects, e.g. Exopodites 
of Pereiopods, resembled First 
Young Stage. 
ES ATEN 
9 9? 3 ” 
GROWTH OF THE YOUNG LOBSTER. 
The larval stages of the American lobster have been fully treated by 
Herrick, who followed its life-history from the time of hatching to the 
tenth stage, when the animal is over one inch long and about three months 
old. He says that the young lobster ceases to swim in the sixth stage. 
In the Laboratory here the young lobsters have been kept for various 
intervals up to ten months. Rearing experiments were carried on in the 
summer of 1902 and the summer of 1904. In the case of the lobsters 
which were kept for several months, it was not possible to tell in what 
morth they were hatched, but as the greatest number of the fry hatched 
out in August, the middle of that month has been taken as the date from 
which to calculate the age of the young lobsters. The growth in the 
cases here cited is possibly abnormally slow. 
A. 1902 Brood—Hatched in August 1902. 
1. September 28-30th 1902.—Megalopa issued from three specimens 
of the large ‘TV ” zoéa. 
», October 30th.—One megalops cast. 
,, November 6th 1902.—Another megalops cast. 
2. October 1st.—A zoéa cast into a zoéa of ‘IV ” stage. 
5, November 7th.—The “IY ” zoéa was partly cast to megalops. 
5, December 5th.—The megalops was dead ; 1-6cm. 
3. October 2nd.—A zoéa cast ; a megalops issued. 
4. November 7th.— A megalops cast. 
5. November 21st.—-A first young stage lobster cast. 
» December 4th.—The soft lobster, second: young stage, was found 
dead ; 1‘4cm. 
6. December 13th.—-A lobster of the second young stage died ; 1‘7cem. 
7. January 15th, 1903.—A first young stage lobster died ; 1-7cem. 
8. Fe 17th.— A first young stage lobster died ; 1:8cm. 
9. »  27th.—A second young stage lobster died ; 1:7cm. 
10. May 29th. —A second young stage lobster cast. 
» dune 1lth.—The soft lobster, third young stage, died 18cm 
11. May 3lst.—A second young stage lobster cast. 
3 . . —The soft lobster, third young stage, died ; 22cm. 
