Gen. -2-2. MeSOCliereS, Norm. & Scott, 1905. 



Generic Characters. Body slender and elongated, with the anterior 

 division only slightly dilated. Cephalic segment less deep than in Collocheres 

 with the rostrum comparatively small. Epimeral parts of the trunk-segments 

 slightly produced. Tail slender, and composed in female of only 3 segments. 

 < 'audal rami long and narrow. Anterior antennae slender, resembling in structure 

 those in Ascomyzon. Posterior antennae moderately strong, with the penultimate 

 joint comparatively short. Oral cone very little produced. Mandibles with the 

 masticatory part comparatively short, tapered and minutely denticulated inside 

 the tip; palp small, uniarticulate. Maxilla? with the lobes likewise rather small, 

 the inner one being the larger. Anterior maxillipeds distinguished by the pre- 

 sence of a secondary spine at the base of the claw. Posterior maxillipeds of 

 normal structure. Natatory legs rather strongly built, with the spines unusually 

 broad, dagger-like. Last pair of legs very small, biarticulate, distal joint tri- 

 angular in shape. 



Remarlcs. With regard to the general form of the body and the long and 

 narrow caudal rami, this genus somewhat recalls the preceding one, from which 

 it is, however, at once distinguished by the different segmentation of the tail, in 

 which respect it agrees with the genus Ascomyzon. In the other structural 

 details also, several peculiarities are found to exist, fully justifying the establish- 

 ment of the present genus. It comprises as yet only a single species, to 

 be described below. 



60. Mesocheres anglicus, Norm. & Scott. 



(PI. LXIV). 



Mcsoclier.es anglicus. Norm. & Scott, Crustacea Copepoda new to science, Ann. & Mag. Nat. Hist. 



Ser. 7. Vol. XV, p. 298. 



Specific Characters. Female. Anterior division of body oblong oval in 

 outline, with the greatest width about equalling half the length. Cephalic seg- 

 ment large and narrowly rounded in front, epimeral edge gently curved; rostrum 

 acutely produced below. Lateral parts of the 3 succeeding segments somewhat 

 angular behind. Last segment very small, scarcely broader than the genital 

 segment. Tail somewhat shorter than the anterior division, and very narrow; 

 genital segment about the length of the other 2 combined, and slightly dilated 



