30 PROCEEDIITGS OF THE NATIONAL MUSEUM. vol.60 



counts are copies of Kr0yer's original and no one else has seen the 

 species. The description given above is taken partly from Kr0yer's 

 text and partly from his figures, with such changes in his nomencla- 

 ture as would make his statements intelligible. If this description 

 be compared with that of Sagum flageUatuTTi, given by the present 

 author in volume 44 of these Proceedings (p. 235), it will be clearly 

 seen that Kr0yer's species belongs to the present genus and not to 

 Lernanthropus where he placed it. 



Heller, in his Reise der Novara^ 1865, in a footnote on page 213 

 relative to the genus Lernanthropus^ said : 



Kr0yer's genus Aethon is closely related to Lernanthropus, if not identical 

 with it. Although Kr0yer does not mention it in his latest work on the para- 

 sitic copepods, It is very evident to me that the new species, Lernanthropus 

 angulatus, there described and figured by him, is identical vsith his Aethon 

 quadratus, previously described. And this is the more likely because both were 

 found upon a West Indian Serranus species. 



A comparison of these two species described by Kr0yer makes 

 Heller's suggestion seem extremely improbable, and for the follow- 

 ing reasons : In Aethon the cephalothorax is three-fourths as wide aq 

 the posterior body, from which it is separated by a distinct neck; 

 the dorsal plate covering the posterior body is as wide as the free 

 thorax; the first antennae are small and insignificant; the third 

 swimming legs are close together on the median line, are only one- 

 eighth the length of the posterior body, and are folded like those of 

 Lema?ithropus, projecting obliquely from the ventral surface. 



In the present species, which is the second one described by Kr0yer, 

 the cephalothorax is as wide as the posterior body ; there is no neck ; 

 the dorsal plate covering the posterior body is as wide as the free 

 thorax; the first antennae are large and prominent; the third legs 

 are flattened into laminae, which are as long as the posterior body, 

 and cover its entire ventral surface. Kr0yer said nothing about the 

 fourth legs in Aethon, and presumably they did not possess the 

 peculiar flagella which he noted in the present species. Such dif- 

 ferences preclude Heller's suggestion of the identity of the two 

 species. The genus Aethon probably becomes a synonym of Ler- 

 nanthropus, but retains its own specific name, and hence becomes 

 Lernanthropus quadratus. 



Genus LERNANTHROPUS Blainville. 



Lernanthropus Blainville, Journ. de Physique, de Chimie, d'Hist. Nat, 



vol. 95, 1822, p. 444. 

 EpachtJies Nobdmann, Mikrographische Beitrage, 1832, pt. 2, p. 45. 

 Lernanthropus Bttbmeistkb, Act. Acad. Caes. Leop. Carol. Nat. Cur., vol. 17, 



1833, p. 303. 

 Aethon Kb0yeb, Naturhistorisk. Tidsskrift, ser. 1, vol. 1, p. 257, pi. 2, fig. 9, 



1837. 



