572 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.55. 



The cement glands and ovaries may be distinguished near the lateral 

 walls of the trunk, but as yet they are only partially developed. 



In an older specimen (fig. 18) the lateral processes of the cephalo- 

 thorax are more pointed and relatively larger, the head has moved 

 to the anterior margin and is plainly visible dorsally as well as ven- 

 trally ; the neck and trunk have enlarged relatively in diameter and 

 the posterior processes have elongated considerably, are much twisted, 

 and have begun to branch. This specimen shows the antennae and 

 mouth parts admirably, and it will be well to describe them in detail. 

 The first antennae are three-jointed processes projecting from the 

 anterior margin of the head near the center, just above and inside 

 of the second pair. The basal joint is much the largest and tli-i 

 terminal joint is a minute knob on the tip of the second joint near 

 its inner margin ; these antennae are destitute of spines or setae. The 

 second antennae are three- jointed, the basal joint much the largest; 

 they start from the anterolateral corners of the head and curve diag- 

 onally inward and backward across the face, almost meeting on the 

 midline. On the tip of the terminal joint are two processes arranged 

 like a chela, one dorsal and the other ventral and a little lateral. 

 Between these antennae lies the mouth tube which is conical and 

 inclined forward and downward. On either side of the tube is a 

 short process or knob, the first maxilla, tipped with a tiny spine. 

 Posterior to the tube is the second pair of maxillae, each of which 

 is a one-jointed, fingerlike process, with a small claw on its tip. 



A short distance behind these is a pair of large fleshy processes, 

 which stand out prominently from the ventral surface of the head; 

 their adjacent surfaces are flattened together and fused on the mid- 

 line so that the two form a hemisphere whose posterior surface, 

 'dM'SLj from the mouth, is divided by a shallow median groove. On 

 this posterior surface at the bases of the processes, where they easily 

 escape notice, is a pair of one-jointed maxillipeds. Each consists of 

 a swollen joint, pointed at the tip and armed with a stout and 

 strongly curved claw and a long spine on the inner margin (fig. 10). 

 These are so overshadowed by the large padlike processes in front 

 of them that they can not be of any service to the matured female, 

 but they probably assist it in securing its first hold upon its host, 

 and in boring its way through the skin into the underlying tissues. 

 A short distance behind the maxillipeds are the bases of the first 

 swimming legs as is shown by the usual chitin ridge on the surface 

 and by muscles beneath the skin. The legs themselves are broken 

 off, but Rathbun obtained one of them and has given an ex- 

 cellent drawing of it. The basal joint is ovate and at the tip are two 

 minute one- jointed rami, without spines or setae. There was a second 

 pair of legs opposite the posterior margin of the lateral processes, 

 but no traces of any others. 



