REPORT ON THE AMPHIPODA. 1203 



stylets or uropods] are quite unequal," a character which, in view of Chosroes, might be 

 included in the definition of the genus. In the expression " bod} r much compressed" he is 

 evidently not referring to lateral compression, but to that between the dorsal and ventral 

 aspects of the animal, for which the more usual phrase would now be — body much 

 depressed. 



Icilius clams, n. sp. (PI. CXXXIIL). 



Head and peraeon not compressed laterally, rostrum small, the perseon widest at the 

 fourth and fifth segments ; the seventh segment dorsally produced backwards in a 

 central tooth or angular process ; the first and second segments of the pleon produced in 

 like manner, the fourth segment of the pleon much longer than the fifth and sixth 

 united, but from the doubling over it of the third segment its length is not perceived 

 until it is separated from the third segment ; the first three segments have the lower 

 margins convex, the hinder sinuous, the postero-lateral angles acute ; the sixth segment 

 broader distally than at the base, a little upturned. The skin in many parts covered 

 with. rows of little dentate scales (see fig. gn.l). 



The Eyes set on the sides of the head are prominent, almost spherical, the ocelli of 

 which they are composed being long, narrow, and very numerous. 



Upper Antennae. — The first joint not so long as the head, a little longer and thicker 

 than the second joint, the third thinner and much shorter than the second ; all three 

 carrying several groups of slender spines ; of the flagellum there are fourteen unequal 

 joints remaining, the first the longest, some, perhaps all, having long apical spines, and 

 being a little dilated distally at the insertion of the slightly feathered spines ; the 

 secondary flagellum has a single slender joint, not so long as the first of the primary, 

 but it appears to have one or more joints missing. 



Lower Antenna*.. — The first and second joints short, the gland-cone narrow and 

 small, not extending along the third joint; the third joint scarcely so long as the 

 united first and second, carrying spines in pairs at two or three points ; the fourth joint 

 about three times as long as the thjrd, with several groups of spines ; the fifth joint more 

 than once and a half as long as the fourth, with numerous groups of spines along the 

 lower margin and along the side ; of the flagellum there are thirty-eight joints remaining, 

 those at the distal end very long and narrow, the whole number together much longer 

 than the long peduncle. 



Upper Lip. — There is a shallow emargination in or near the centre of the distal 

 margin, the middle of which is smooth, but has on either side a fur of close-set short cilia 

 directed towards it, the more remote cilia being longer and not closely set. 



Mandibles. — -The cutting edge with six teeth ; the secondary plate with four, this 

 plate forming a thin lamina with very sharp teeth on the right mandible, while on the 



