NO. 1531. ADDITIONAL NOTES ON THE ARGULID.E— WILSON. 417 



their true hosts. As the previous description" of this species was 

 made entire!}' from preserved specimens, it will be well to note here 

 the color of the living' adults. 



The body in both sexes is beautifull}'^ transparent and of a soft yel- 

 low color, like rich cream. Against this background the grooves on 

 the dorsal surface of the carapace and the spots over the semen recep- 

 tacles in the female and over the testes in the male show a clear cinna- 

 mon brown, while the claws and spines on the ventral surface are a 

 darker brown, tinged with reddish. 



The small spots which cover the entire dorsal surface, and from 

 which the species was named, are a light brown, distinctly visible 

 even to the naked eye. 



The two females deposited their eggs that same evening upon the 

 sides of a wide-mouthed bottle in which the}^ had been placed. 



The eggs were arranged in single straight rows, not end to end like 

 those of inegalops, but the tirst one inclined to the right, the second 

 to the left, the third to the right, and so on. 



The jelly envelope assumes a form characteristic of this species and 

 much resembling that in A. catostmni and A. aniericanus^ with this 

 difference. In catostomi the jelly hardens into rows of papilla?, all 

 about the same size, and running lengthwise of ^he Q%^\ where the 

 eggs come together these papillae rows simply fuse into one another. 

 In ainerlainus there are similar longitudinal rows in which the papilla? 

 are the same size, and in addition there are also a few scattered masses 

 of jelly, some of which are nearly two-thirds as large as the entire 

 ^%g' But they are scattered at random, and there are never more than 

 one or two for each Q^'g. Here in )iiacvIosus the longitudinal rows are 

 the same as in the other two species, and there are in addition thelarge 

 masses of ]Q\\y. But instead of being scattered they are arranged with 

 perfect regularity, a row of them standing out like the spokes of a 

 wheel at the junction of every two eggs, and at right angles to the 

 long axis of the Q,gg row. 



The eggs are twice the size of those of umericanus^ measuring 0.64 

 by 0.43 mm., exclusive of the jelly envelope. They are light yellow 

 and transparent when first laid, but become darker and opaque about 

 the fourth day. The eyes appeared on the eleventh day, and the eggs 

 began to hatch on August 24, sixteen days after they were laid, about 

 the same length of time as that required for the americanus eggs. 

 They did not all hatch at once, but kept coming out for about sixty 

 hours. They were kept immersed in the lake for the first twelve days, 

 the temperature of the water for that time averaging 76^ F. They 

 were then removed to an aquarium in which the water temperature 

 stood nearly constantly at 72" F. 



«Proc. U. S. Nat. Mas., XXV, p. 715. 

 Proc. N, M. vol, xxxii— 07 27 



