Preliminary Notice of a Parasitic Copepod. 249 
definite in form as to lead one to mistake them for true 
appendages. The shape of the body in the female resembles, 
in quite a marked degree, that of Anchorella triglw, Claus, 
a species belonging to the family Lernaopodide ; but on the 
other hand, the head shows a similarity to that of Cestopoda 
amplectans,a member of the same family. The head, as in 
these two species, is fairly distinct from the thorax; but, 
probably on account of the intricate connection with the vas 
deferens, I was unable to make out a distinction between 
thorax and abdomen. As regards appendages, I experienced 
considerable difficulty in their dissection and in understanding 
their arrangement, on account of their being so thickly 
crowded together; the situation of the head, as in the 
Lernzopodid, being such that the appendages lie close 
together on the ventral surface. 
The same difficulty has been experienced by others who 
have studied the Lernzopodide. In this female the only 
appendages which I made out at all distinctly were the first 
three pairs, presumably the two pairs of antenne and the 
mandibles. The first pair of antenne is much smaller and 
not nearly so prominent as the second pair. They show 
a trace of segmentation; but this is by no means so distinct, 
nor are the segments so numerous, as those of the second pair. 
The second antennz possess a main joint, from whose ends 
two branches project. They extend farther forward, and 
tend to conceal the first pair. At the anterior head extremity 
of the older specimen I noticed a sucking organ, which is 
provided with a ventral and a dorsal fixing process. The female 
further shows a very slight niching on the dorsal surface of 
the head, and this is noteworthy, because, in the male, we find 
a much more prominent and extended niching of the dorsal 
surface. The female showed little or no trace of segmentation. 
Description of the Male.—I obtained only two of these male 
parasites at different stages, and these possessed rather dis- 
similar characters. In both, however, there exists a very 
distinctive niching on the dorsal surface. This dorsal niching 
has an appearance not unlike that seen in the same position 
in Canthocamptus minuticornis and other species. The better 
preserved of the two specimens showed a division of the 
