432 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxiii. 



of the male the rami of the third legs are two-jointed on one side and 

 one-jointed on the other, while those of the fourth legs are both 

 one-jointed. In the ventral view both rami of the fourth legs, and 

 the endopods of the third legs are one-jointed; all the other rami are 

 two-jointed. 



Such data are hardly sufficient to decide whether the two specimens 

 are the male and female of the same species or not, nor even that they 

 certainly belong to the genus Pandarus. 



None of the genera here considered have one-jointed endopods in 

 the third pair of swimming legs. But this is manifestly an error on 

 Beneden's part, and the ramus should have two joints like the exopod. 

 With this one correction, assuming that all the details are accurately 

 stated, the appendages, the general body form, the relative size, and 

 shape of the different segments, and particularly the narrow and 

 elongated posterior lobes of the carapace, correspond exactly with 

 those found in Nesvppus males. 



And at the same time they are radically different from those* of 

 Pandarus males ; in particular the present species lacks the accessory 

 lobes on the posterior margin of the carapace, there are no legs visible 

 on the genital segment, and the abdomen has but a single joint. 

 Furthermore Nesipj)us males are usually found in company with both 

 sexes of other genera on the outside of the host, while the adult 

 females are confined to the gill arches in the throat. "We may reason- 

 ably conclude, therefore, that while the female undoubtedly belongs 

 to the genus Pandarus, the male is not a Pandarus at all, but a 

 Nesipjms. 



Later in the same year Beneden published another paper, entitled 

 Some new Caligids from the Coast of Africa and the Azores Archi- 

 pelago, in the same periodical." 



The second of the new forms described he calls Nogagus angustatus, 

 of which he claims to have found both sexes. 



But his mistakes here are even worse than those of the former 

 paper; in the first place his species is not identical with Gerstaecker's 

 Nogagus angustulus, as he claims. The difference in spelling is 

 accounted for by the fact that in Gerstaecker's paper (1854) the 

 specific name is spelled ^'angustulus" in the text, and "angustatus" 

 in the explanation of the plates. The former was evidently' the one 

 intended by Gerstaecker, and it is quoted by Steenstrup and Lutken, 

 and by Bassett-Smith. If any reliance can be placed upon Beneden's 

 figures, there are enough differences, even in a dorsal view, to distin- 

 guish the two species at a glance. (See N. angustulus, p. 351.) 



Again, supposing the male had been the same as Gerstaecker's 

 species, it was long ago proved that the entire genus Nogaus is made 



a Pages 241 to 262. 



