}24 THE VOYAGE OF H.M.S. CHALLENGER. 



from that in (Edicerus saginatus. The inner plate of the first maxilla is large and furnished 

 with several strongly ciliated hairs. From regard to the marsupial plates and their relation 

 to the branchioe, he would place (Edicerus and Aceros rather with Plwxus and the like than 

 near to Gammarns. In the form of the hands of the gnathopods he finds an approach to 

 the subfamily of which Leucothoe is the type. Whether Aceros with a short penultimate 

 syllable should be considered pre-occupied, because a genus of birds was called Aceros, with 

 a long penult, is perhaps an open question. 



For the new genus, Iduna, or at least for the two species which constitute it, he gives the 

 following characters : — The accessory flagellum is especially long, while the principal 

 flagellum of the upper antennse is short. The lower antennae are strong and almost subpedi- 

 form. The molar tubercle of the mandibles is small ; tlie inner plate of the first maxillaj is, 

 as in Eusirus, oval and furnished with a single plumose seta ; the biting-plates (Tygge- 

 plader) of the maxillipeds are small and their palps much elongated. The first two pairs 

 of legs are provided with strong clasping hands, their fourth joint sending out from the 

 lower hinder angle a strong process, as in Leucotlio'e ; the following pairs of legs are very 

 thin and long, the last pair is very long; the uropods (Halef0dderue) are long and the telson 

 deeply cleft. The first side-plate (Epimer) is strong, larger than the next one. Thus they 

 show great agreement with Eusirus, and differ much from the typical species of Gammarns. 

 The marsupial plates, he says, in this genus are small, the branchite long and broad ; the 

 palp in the first maxillee has the first joint short. Alike, he says, in Eusirus and Iduna, the 

 inner plate of the first maxillfe is larger than [in] the other [members of the group], but 

 in all furnished only with one bristle. In 1876, he says that this plate in Lilljehorgia 

 Jissicm-nis has one very long plumose seta and a smaller seta not plumose, and that in 

 Eusirus cuspidatus it has two plumose setae. 



His genus Epidesura, he says, in many characters approaches Dezamine, Leach. The form of the 

 antennae is as in Dexamine; the mandibles, however, have a very thin, weak, triarticulate 

 palp ; the palp of the first maxillae is bi-articulate, and the inner plate is furnished with six 

 ciliated hairs ; the biting-plates of the maxillipeds are large, the palps small, thin, with their 

 fourth joint forming a small finger (Klo). The marsupial plates are especially large, 

 furnished on the edges with close-set, long hairs ; the branchiae of the last thoracic legs are 

 of the same peculiar form which is found in Ichnopus ; the two last segments of the pleon 

 are coalesced and the telson is divided ; the body is strongly compressed. 



The new genus Amphithopsis is instituted for those species (taken from Paramphifhoe, Bruzelius, 

 and united to two new ones), which have — an elongate, compressed body with moderate 

 epimera and long antennae ; the inner plate of the first maxillre furnished with four to five 

 long, thick, plumose setse ; the inner plate of the second maxillie with many simple 

 setae at the extremity, but several on the inner side very strong and plumose ; the 

 maxillipeds large, with palps of moderate length ; the two first pairs of feet with hands of 

 nearly the same size, small ; the third and fourth pairs of legs with the fifth joint very long, 

 longer than the third joint ; the telson simple ; the last uropods with the branches long, 

 often unequal; the marsupial plates much larger than the branchiae, closely margined with hairs. 



In the new genus Podoceropsis, the body is somewhat depressed, the epimera small, the 

 antennae long and thin, the upper attached far in advance of the lower at the point of the 

 projecting head. Their peduncle is very long, longer than the flagellum and without 

 accessory flagellum. The mandibles are large, at the extremity divided and dentate, with 

 long triarticulate palp. The palp of the first maxiUae is biarticulate, the inner plate 

 small and thick. The maxUlipeds are long, narrow, with the fourth joint of the palp 

 divided into two joints, of which the last forms a pointed nail (Klo.). The two first 

 ("sidste," last, by an obvious mistake for "fcirste," first) pairs of feet having the fifth joint 

 forming a clasping hand, which in the second pair is much larger than in the first, and not 



