242 Miscellaneous. 



are simple wait-like tubercles, each furnished with two setaa. As a 

 character acquired by adaptation and quite peculiar to the genus, 

 special interest appears to attach to the presence of abouty?/i^?/ pairs 

 of dorsal, and the same number of ventral, scale-lilc, Jtiieli/ striated 

 elevations, which are obliquely elevated and extend over the whole 

 length of the thorax to the commencement of the abdomen, and are 

 of essential service in the gliding-movements beneath the scales of 

 the fish. To these is added, at the anterior end of the head, a 

 median dorsal tubercle, which is clothed transversely with close-set 

 chitinous bands, and probably aids in the boring and mining move- 

 ments. 



Although there could be no doubt that in the parasite hero de- 

 scribed we had to do with a female Lernaean in the egg-producing 

 stage, the search for younger and smaller forms led at once to an 

 acquaintance with the males and females in the copulatory stage. 

 In this phase of development the sexual animals attain scarcely one 

 third of the length of tlie pregnant female, and nearly approach the 

 type of the free-swimming jointed Copepoda. The larger males 

 have retained nearly the normal segmentation of the body, and 

 possess two pairs of swimming-feet modified for clinging, followed 

 on the third pectoral segment by a third pair of simple stumps. 

 The smaller and more feebly constructed female shows exactly the 

 same construction of body, except that the segmentation becomes 

 quite retrograde in the thorax and abdomen, which latter tapers 

 towards the extremity and runs out into two furcal joints. In the 

 male animal the thorax consists of five, and the abdomen of four 

 t-har])ly separated segments, of which the genital segment is unusu- 

 ally large, but nevertheless it is exceeded in size by the terminal 

 segment. The latter appears almost scutiform and considerably 

 elongated, in connexion, as may be at once ascertained, with the 

 position of the testes, u'hich are moved down into the terminal 

 segment — a very interesting change of position quite unknown to me 

 in any case elsewhere among the Copepoda, but which has become 

 normal in the nearly allied Argulida3, formerly referred erroneously 

 to the rhyllopoda. Tlie spermatophores are remarkable for their 

 extraordinary size, not only filling the genital segment, which is 

 furnished with two plates, but extending forward nearly to the limit 

 of the antepenultimate thoracic segment. The prehensile antennae, 

 in the copulatorj- stage, show tlie type of the Corycseida^, and be- 

 come afterwards very essentially simplified in the females ; the parts 

 of the mouth also difter considerably from the form in the pregnant 

 .^tage, inasmuch as they are destitute of the sucking-proboscis, and 

 possess a different form of the maxillary foot-pair, agreeing in the two 

 texes. The presence of two wing-like plates on the back of the 

 second thoracic segment seems worthy of notice ; they remind one 

 of the characters of the group Pandaridaj. In the female these 

 become considerably retrograde, but are still retained even in the 

 egg-producing stage as two-pointed chitinous pieces. — Anzeiyer Ic. 

 Akad. Wiss. in Wien, December 2, 1886, p. 231. 



