N0.1W3. PARASITIC COPEPODS— WILSON. 467 



dorsal view of the female in 1850. Hoeven in 1857 published a paper 

 on Cecrops and '^Lxrnargus/' which contains the only reall}" .^ood 

 figures that have ever appeared; but even these show many mistakes 

 and imperfections. 



In 1883 Ilesse presented what he claimed was a new species of 

 Cecrops, and which he named C. achantii-vulgaris. The name is cer- 

 tainly wrong for the shark genus on which Hesse's specimens were 

 found is AcantJiias (from aKavdiag) and not Achantius, and even if 

 Latinized the genitive would not be spelled as Hesse has given it. 

 Furthermore, this so-called species is based upon a single female speci- 

 men, which, from Hesse's description and the little that can be learned 

 with certainty from his figures, can not possibly belong to the genus 

 Cecrops. 



He has represented the first three thorax segments fused with the 

 carapace; neither the genital segment nor the abdomen are men- 

 tioned in the text, nor can they be made out in the figures. 



The swimming legs also are not mentioned in the text, and even 

 a chirographic expert could not decipher them in tile figures. 



And finally, the second maxillipeds with their "thumb" in the 

 form of a peduncled ball, shutting down into a cavity, are entirely 

 unlike those of Cecrops. The size of Hesse's specimen, 6 mm. in 

 length, the fact that it had no egg-strmgs, and the general appearance 

 of the body, suggest that it is probably a very young female. But its 

 true location must be left f jr future investigation; all we can decide 

 at present is that the species, as Hesse has described and figured it, 

 does not belong in the genus Cecrops. 



Five years later, in 1SS8, Hesse published his thirty-seventh paper 

 on New antl Rare Crustacea of the Coast of France, which is entirely 

 concerned with these two genera, Cecrops and " Lsemargus." 



The paper is profusely illustrated, but not a single one of the 25 

 figures representing Cecrops latreUlii is correct, and all of them 

 which show the entire animal are wretchedly confused. If compared 

 with similar views given by the other authors mentioned, it would 

 never be guessed that they were intended to represent the same ani- 

 mal. The third legs of the female, visible for the entire width of the 

 body m dorsal view, the "plaque" (really the dorsal plates of the 

 fourth segment) with its wonderful design of the cross and crown, and 

 the two large lobes of the genital segment, "whose margins are rolled 

 up in the form of a volute," are especially bizarre. 



In the following year, 1889, Thomson gave several figures of Cecrops 

 in his Parasitic Copepods of New Zealand, the most valuable of them 

 being enlarged views of the four pairs of swimming legs. There are 

 thus three sets of figures, those originally given by Leach, the excel- 

 lent ones by Hoeven, and these by Thomson, which rej^resent all 

 that IS known of the genus up to date. It is hoped that the figures 



