AMERICAN PARASITIC ARGULID.^)— WILSON. 659 



It will be noted that this account differs considerably from that of 

 Jurine. In the present instance, as in the case of A. catostomi^ already 

 cited, no female deposited her eggs in two columns, but every time 

 they were arranged in a single row. This was due to the fact that 

 the short move ahead, instead of being a one-sided affair, throwing 

 the body at an oblique angle to the line of progress, was a uniform 

 and even advance, the body remaining always parallel with the line of 

 advance. All through the (^.gg laying the females manifest considera- 

 ble excitement; the legs, with the exception of the posterior pair, are 

 moved incessantly and Avith great rapidity in the same way as when 

 swimming. As soon as one row of eggs is finished the female 

 darts rapidly about the a((uariuni for some little time, twisting and 

 turning somersaults as if crazed. These motions gradually slow down 

 and finally cease, when she l)egins to hunt for a new place in which to 

 deposit another row of eggs. These observations, coupled with the 

 fact that females with their ovaries only half full of ripe eggs have 

 been repeatedly taken upon fish frequenting the bottom, make it rea- 

 sonably certain that they do not deposit their eggs all at once, but at 

 intervals, and in the meanwhile they ma}" even obtain a square meal 

 from some convenient fish. 



The female carries sperm, obtained from previous copulation, in 

 heir abdominal pouches, and each ^gg is fertilized as it is laid. If 

 one of the eggs be removed shortly after deposition and examined 

 under a high power the spermatozoa can be plainly seen swarming 

 around the jelly envelope. 



Notwithstanding this method of fertilization, the iigg laying excites 

 the males even more than the females, and they dart about in a vain 

 endeavor to get hold of some of the latter. 



At first two species {nuyalopf^ and Jaticauda) were mingled in the 

 same dish; all of the females that were laying were megalopn^ while most 

 of the males were hif'icauda. But this fact did not seem to make any 

 difference; the htftc<iii<hi males were as uuu-h excited as those of 

 )ne(jah)pi<^ and, neghn-ting the females of their own species, which 

 were quiet and had finished their laying, they made cxciy ctfort to 

 seize the 'megalop>< females; ])ut, together with the nuyalop^ males, they 

 were constantly repulsed. K\'idently the copulation takes place pre- 

 vious to Qgg laying, and the femule relies wholly upon the sperm stored 

 lip in the seminal pouches. 



These eggs of ^l. iitegalopxiXYQ ellipsoidal, like those oi foliaceux and 

 (uitostoini^ but are not as large, being only u.^r) nun. long and 0.28 

 mm. wide, and yet we shall presently see that the larva which emerges 

 from them is one of the largest yet described. 



The eggs are light yellow when first laid, afterwards becoming dirty 

 and brownish, but never as dark as those of catostoiui. 



