418 



the base to a conical prominence tipped with a delicate bristle, inner portion 

 exserted to a strong spiniform projection flanked inside by 2 slender bristles 

 and outside by a single smaller one. 



Colour not yet ascertained. 



Length of adult female 0.70 mm. 



Remarks. This is another form at first described by Th. Scott as a 

 species of the genus Tetragoniceps, but recently removed from that genus Indeed, 

 the present form exhibits several very striking peculiarities, which seem fully to 

 justify its separation from any of the 4 preceding genera. It may here be 

 noted, that the 5 genera treated of in the preceding pages, though apparently 

 well defined, exhibit a certain relationship to each other distinguishing them from 

 the other genera included in the family Canthocamptidce. It therefore appears 

 not improbable that in future it will be found appropriate to combine these genera 

 into a separate family, which in some respects would seem to approach that of 

 the Cylindropsyllidce. 



Occurrence. Only 2 female specimens of this form have as yet come under 

 my notice. They were found in the same samples as those from which the 3 

 preceding forms were derived. 



Distribution. Scottish coast (Scott). 



Gen. LeptOmeSOChra, Gr. 0. Sars, n. 



Generic Characters. Body narrow and elongated, with rather thin integ- 

 uments. Rostrum obsolete. Genital segment in female not subdivided. Caudal 

 rami comparatively short, with the apical setae of normal structure. Anterior 

 antennae very Blender and quite unarmed; those in male slightly hinged. Posterior 

 antennae with the proximal joint distinctly subdivided, outer ramus small, bi- or 

 uniarticulate. Mandibles with the masticatory part narrowly exserted, palp well 

 developed, biarticulate, with the basal joint more or less expanded and in some 

 cases carrying a rudiment of an outer ramus. Maxillae small, with the exopodal 

 and epipodal lobes imperfectly developed. Anterior maxillipeds short and stout, 

 with the distal joint produced inside to a very long claw-like spine, basal seti- 

 ferous lobes imperfectly developed, apical part inconspicuous. Posterior max- 

 illipeds normal. 1st pair of legs of comparatively feeble structure, though 

 distinctly prehensile, inner ramus longer than the outer and in most cases biarti- 

 culate. The 3 succeeding pairs of legs well developed, with the outer ramus 

 rather large, inner much shorter and biarticulate, except in the 4th pair, where 

 it is more generally composed of 3 well-defined joints; natatory setae in both 



