of the Norih Atlantic and of North-Western Europe. 643 



Genus 1. Crossophoeus, G. S. Brady. 

 (" Report ' Challenger ' Ostracoda," 1880.) 



Shell in general form as in Cypridina, the hinder extremity in the type species 

 very broadly rounded ; textm^e firm and calcai-eous ; antennules with second joint 

 only slightly hmger than the third, which on the front side is much longer than 

 the fourth, and equal to the fifth joint, this latter in both sexes furnished 

 with a long filiferous sensory seta ; sixth joint very short ; last joint in both 

 sexes terminating in three long setae and several shorter ones. Antennae have the 

 appendicular branch in ? three- jointed, the last joint terminating in a long seta, 

 and in $ like that of Cypridina, of much larger size formed for grasping, tlie 

 last joint falcate, and closing with the second. Mandible having a cleft, setose 

 masticating process, and also masticating spines on the first joint of the palp ; 

 both masticating process and spines present in the two sexes. Second maxillae 

 have several upright teeth, curved at the apex, with denticulated edge, as in 

 Cypridina. Caudal laminae furnished with stout ungues alternating with others of 

 much more slender and spine-like character. 



This genus approaches nearest to Philomedes, from which it is distinguislied 

 by the proportionate length of the joints of the antennules, by their having the 

 sensory filiferous appendage present in both sexes, and by the male havin_ the 

 last joint setose in the same way as in the female, instead of bearing the two 

 remarkably long setaj characteristic of Philomedes. The peculiar arrangement of 

 the armatui-e of the caudal laminae is unlike that of any other known genus. 



Crossophorus imperator, G. S. Brady. 



(PI. LIII., figs. 1-11.) 



1880. Crossophorus imperator, . . Brady, G. S. " Report ' Challenger ' Ostra- 

 coda," p. 158, pi. xxxviii., figs. 1—10. 



Shell fii'm, porcellanous, and polished ; seen from the side very broadly and 

 regularly oval ; height equal to three-fourths of the length ; antennal sinus of 

 moderate size, and expanded laterally so as to produce two obliquely-placed 

 depressed areas on the anterior surface of the shell ; rostral process curved down- 

 wards, and sharp ; posterior extremity ver}' broadly rounded ; dorsal and ventral 

 margins equally convex, not the slightest angularity on the infero-posteal portion 

 of the shell. Seen from above the form is oblong-ovate, widest in the middle, 

 subacuminate in front, and rounded behind; width equal to more than half 



