658 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxv. 



deposit her egfgs. Having- found one .she crawled along slowl)' over 

 it by the walking motion of her sucking discs. When she had 

 advanced far enough to compensate for the length of her body she 

 stopped and violently contorted and twisted her thorax and abdomen, 

 bending them from side to side and backward and forward. During 

 these contortions an ^gg could be seen descending the oviduct toward 

 the opening between the posterior pair of legs. Just as the Qgg 

 reached this opening the thorax was bent sharply upward (dorsally) 

 away from the glass; at the same time the abdomen was bent sharply 

 downward (\'entrally) toward the glass, so that thorax and abdomen 

 formed a right angle with each other, the angle being held some little 

 distance away from the surface. Into the space thus formed the egg 

 was protruded, ])eing seized tirmh^ on either side by the basal joints 

 of the posterior pair of legs as soon as it emerged from the opening 

 of the oviduct. The posterior lobes on these basal joints were pulled 

 as far forward as possible and then drawn together, catching the Qgg 

 between their inner surfaces and carrying it l)ackward into the little 

 space under the flexed thorax-abdomen. Here it was pressed for an 

 instant against the support (glass) to which it adhered firmly. 



The Argulus then moved forward a distance equal to the long diam- 

 eter of the Qgg with its jelly envelope and the process was repeated. 

 The eggs thus adhere to each other in rows as well as to the glass, 

 each row containing ten or a dozen eggs and being usually quite 

 straight. The process is rather slow, a little more than a minute 

 (seventy seconds) being occupied in the deposition of a single i}gg. 

 In this species one female did not lay more than -lU or 50 eggs, and 

 often the last ones were deposited singly and scattered about indis- 

 criminately. 



It seems probable, however, that this number does not represent 

 the entire batch of eggs, but that the fe^nales had deposited a part of 

 them before being captured. 



After the first one or two eg'gs are laid the al)domen of course has 

 to ride up over them as the Argulus moves forward. 



The liase of the anal sinus rests upon the rounded upper surfaces of 

 the eggs, which it fits snugly, while the lateral edges are bent down 

 on either side. The abdomen thus curved over the eggs pro) )a])ly acts 

 as a guide for tlu^ Argulus, enabling her to place the eggs in approxi- 

 mately straight rows. 



Furthermore, it would seem as if the anal papilla?, which in megalopx, 

 as so often in other species, are situated at the very base of the sinus, 

 might act as feelers, slipping over the eggs lengthwise and down into 

 the hollows between them, enabling the Argulus to tell when she had 

 moved forward just the right distance. 



At all events, whether the rows are straight or crooked, the eggs 

 are always the same distance apart. 



