of the North Atlantic and of North-Western Europe. 653 



exserted below the middle, and there forming a distinct and prominent angle ; 

 rostrate projection moderately prominent, sub-truncated in front, with a distinct 

 angle below, but not above ; eyes very large ; limbs little differing from those of 

 C. mediterranean length 2"62 mm." 



Two females taken by Prof. G. 0. Sars, at Messina, Sicily, in 10-20 fathoms 



We have not seen this species. 



Genus 3. Philomedes, Lilljeborg, 1853. 



(= Cypridina, Lilljeborg, ? 1853, = Philomedes, Lilljeborg, $ 1853, 

 = Beadycinetus, G. 0. Sars, ? 1865.) 



Shell of female more or less ovate, either smooth, hispid, or highly calcareous, 

 and sculptured with pittings or ribs ; antennal sinus usually opening down- 

 wards ; rostral process obtusely terminated, overhanging the sinus; infero-posteal 

 angle often angularly produced. In the male the shell is longer in proportion to 

 the height, and the antennal sinus is of different form, being widely open forwards, 

 as well as downwards, because the rostral process is here truncated anteriorly, 

 and rises almost at a right angle from the bottom of the antennal sinus, which 

 it does not overhang ; in rugose forms, the valves also of the male are much less 

 sculptured than in the female. 



Eyes of ? small or wanting, of S well developed. Frontal tentacle long 

 and slender. Antennules six-jointed (PL lvii., fig. 12 ; fourth joint without any 

 sensory organ in ? , but in S (Ph lvii., fig. 1) with such an organ, which 

 consists of a large annulated appendage beset with numerous filaments, extremity 

 of the limb ending in ? in several subequal setse, in 3 two setee are immensely 

 developed, of very great length, and usually carried reflexed upon the limb. 

 Antennas with appendicular branch small in ? (PI. lvii., fig. 13), but in $ 

 (PI. lvii., fig. 2) much larger and prehensile, the last joint closing on the second. 

 Mandible of ? having the basal joint furnished with a masticating process which 

 is cleft at the apex (PI. lvii., fig. 14); first joint of palp, with peculiar formed 

 masticating spines at the base, and furnished at the dorsal extremity with a small 

 appendage; third joint only slightly narrowing to the extremity, last joint 

 terminating in ungues, the S is wholly destitute of the masticating process and 

 masticating spines (PI. lvii., fig. 3). Most of the remaining limbs and the caudal 

 laminae are not markedly different from those of Cypridina. The second maxilla, 

 however, differ considerably in minute detail ; in the female there are only four 

 lobes, the place of the outermost lobe being occupied by a series of teeth, the 

 uppermost of which is large and triangular, and not denticulate on the margin ; 

 beyond the tooth the group of the spine-formed setee, and other setae characteristic 



lEANS. HOT. -Sm&. SOC, N.S., VOL. V. PAET XII, 4 2 



