20« 



HANDBOOK OF INVERTEBRATE ZOOLOGY. 



and 106, r), the length of which varies greatly in different 

 species. 



e. Near the posterior edge of the middle of the dorsal 

 surface the carapace is prolonged to form a slender, pointed 

 dorsal spine (Figs. 105 and 106, d), the length of which 

 also varies greatly in different species. 



Fig. 105. 

 Fig. 105. — Zoea of Callinectes, one day after hatching, seen from the 

 left side, magnified about eighty diameters. (Drawn by W. K. Brooks 

 from a slcetch from nature by E. B. Wilson. ) 



A. Antennule. An. Antenna, a. Abdomen, c. Carapace, d. Dor- 

 sal spine. E. Eye. L. Labrum. I. Lateral spine, mp^. First maxilli- 

 ped. mp^. Second maxilliped. r. Rostrum. L Telson. 



/. In Callinectes the sides of the carapace give rise to a 

 pair of shorter lateral spines (Figs. 105 and 106, 6), which 

 are absent in the zoeas of many crabs. 



