REPORT ON THE AMPHIPODA. 1471 



same time required of the preoccupied specific name. Bovallius, in his Systematical List 

 of the Hyperina, does not mention Claus' Eutyphis serratus, perhaps considering it to be 

 the same with Typhis ferus, Milne-Edwards, 1830, figured in the Annales des Sciences 

 naturelles, t. xx. pi. xi. figs. 8-18. if those figures, however, may be trusted, the present 

 species, though agreeing in respect of the lower antennae of the male and in various 

 other points, differs in several particulars ; in the first gnathopods the process of the 

 wrist, which is pectinately toothed along both margins, at its base is closely adjacent to 

 the hand, not separated from it by a space ; in the second gnathopods the third joint 

 is more out-bowed in front, and the wrist has the distal process as long as the proximal 

 part ; the third joint of the first perseopods is of less proportional length ; and whereas 

 in Milne-Edwards' figure the rami of the third uropods are subequal, the inner if 

 anything the shorter, in Claus' species the outer ramus is much shorter and narrower 

 than the inner, which is only feebly jointed to the peduncle, if not coalesced with it ; 

 the telson is also broader at the base than the length in Claus' species, but the reverse in 

 Milne-Edwards'. In the Challenger specimen the apex of the telson is a little narrowed, 

 not broadly rounded as in Claus' figure. 



Genus Hemityphis, Claus, 1879. 



1879. Hemityphis, Claus, Die Gattungen und Arten der Platysceliden, pp. 4, 12. 



1886. ,, Gerstaecker, Bronn's Klassen und Ordnungen, Bd. v. Abth. ii. p. 482. 



1887. Dithyrus, Bovallius, Systematical List of Amph. Hyper., Bihang till K. Svensk. Vetensk.- 



Akad. Handl., Bd. 11, No. 16, p. 46. 

 1887.? Hemityphis, Claus, Die Platysceliden, pp. 3), 38. 



For Claus' definition of Hemityphis, see Note on Claus, 1879 (p. 491). The points 

 by which Claus distinguishes Eutyphis from Hemityphis are simply, that in Eutyphis 

 (Plat y seel us) the two terminal joints of the hinder male antenna? are very short, and 

 the outer plates of the maxillipeds are slightly concave on the inner margin, while in 

 Hemityphis the two terminal joints of the hinder male antenna? are long (though notably 

 shorter than the two preceding joints), and the inner margins in the maxillipeds are 

 deeply concave. 



Bovallius in 1887 identifies Hemityphis with Dithyrus, Dana, but without giving his 

 reasons. Claus has pointed out that Dana established his genus Dithyrus on a damaged 

 specimen of the female sex, and suggests that the type species, Dithyrus f aba, may be 

 the same as his own Eutyphis inermis. Dana's figures and descriptions do not in fact 

 supply the means of deciding whether he was dealing with a species of Platyscelus or 

 Hemityphis. The figure, which he gives as representing either the first or the second 

 perseopod, by the straight downward-pointed finger is rather in agreement with 

 Hemityphis than with Platyscelus, but on so minute a detail it is impossible to lay 

 much stress, where it has not been observed for a special purpose. According to Dana 



