84 



Part III. — Twenty-third Annual Report 



Stage. 



Cast into 



Special Characters of 



Resulting Form. 



Ilia. 



" LV." 



Pleopods and Telson of Megalops. 



Ilia. 



"IV." 



Ilia. 



Megalops. 



Short Antenna?. 



lllb. 



u jy » 



Pleopods of Megalops. 



1116. 



Megalops. 





Illb. 



j> 





ITI6. 



?> 





III6. 







"IV." 





In some respects, e.g. Exopodites 







of Pereiopods, resembled First 







Young Stage. 



"IV." 





?? 5; 



Growth of the Young Lobster. 



The larval stages of the American lobster have been fully treated by 

 Herriek, 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 

 month 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 " IV " zoea. 

 ,, October 30th. — One megalops cast. 

 ,, November 6th 1902. — Another megalops cast. 



2. October 1st. — A zoea cast into a zoea of " IV " stage. 



„ November 7th. — The " IV " zoea was partly cast to megalops. 



„ December 5th. — The megalops was dead; l'6cm. 



3. October 2nd. — A zoea 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 ; l*7cm. 



7. January 15th, 1903. — A first young stage lobster died ; L7cm. 



8. ,, 17th. — A first young stage lobster died ; l'8cm. 



9. „ 27th, — A second young stage lobster died ; l*7cm. 



10. May 29th. —A second young stage lobster cast. 



„ June 11th. — The soft lobster, third young stage, died l*8cm 



11. May 31st. — A second young stage lobster cast. 



„ „ . —The soft lobster, third young stage, died ; 2*2cm. 



