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HANDBOOK OF INVERTEBRATE ZOOLOGY. 



very minute, active white animals, about a twenty-fifth of 

 an inch in length. When one of these white specks comes 

 to rest upon the side of the glass, pass a dipping-tube 

 down to it, and removing the finger from the top, allow 

 it to be drawn into the tube. Transfer it to a watch- 

 glass, and, examining it with a 

 low magnifying power, ascertain 

 whether it resembles Fig. 118, 

 either with or without the egfor 

 bunches (n) ; if so, it is a 

 Copepod. The females of the 

 fresh-water species are larger 

 and very much more abundant 

 than the males, and as they 

 are therefore the most easily 

 obtained, this account has been 

 written with especial reference 

 to the female, except when the 

 contrary is stated. 



Fig. 118. — Dorsal view of female 

 specimen of Cyclops canthocarpoides, 

 with ovisacs highly magnified. (From 

 Claus, Freilebenden Copepoden.) 



a. First antennae, b. Ocellus, c. Ovi- 

 duct, d. Carapace. e, /, g, h. The 

 four free thoracic somites. i,j,k,l. The 

 Fig. 118, abdominal somites, n. Ovisacs. 



A number of females should be placed in a watch-crystal 

 with only enough water to cover them, and killed by add- 

 ing a small quantity of ether to the water. One or more 

 individuals will then probably be found to present a good 

 view of the dorsal surface for microscopic examination. 



I. In the dorsal view notice that the body is divided 

 into two regions of nearly equal length ; an anterior 



