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transversal folds as an indication of segments, ventral face concave, or more 

 properly grooved along the middle. Cephalic parts narrowly truncated in front, 

 and defined laterally from the wing-like projecting lateral parts of mesosome by 

 deep incisions, its ventral portion forming a narrow quadrangular plate de*eply 

 emarginated behind. Oral area very small, rounded, placed far in front. - 

 Body of immature female nearly quadrangular in outline, scarcely tapering at all 

 posteriorly, hind extremity bluntly truncated, cephalic part narrowly produced. — 

 Adult male narrow, linear, somewhat resembling that of Notophryxus ovoides, 

 but having the metasome considerably more produced, tapering distally, and di- 

 vided into 5 not very sharply defined segments, the last of which carries 2 in- 

 distinctly bifid appendages (the uropoda). — Young male, still in the cryptoniscian 

 stage, resembling that of Dajus, though having the front narrower and the oral 

 sucking disc of smaller size. Colour of female somewhat varying in different 

 specimens, the dorsal face being more or less variegated by a dark brownish 

 red pigment, generally arranged in broad transversal bands. Length of female 

 attaining 3 mm., of male 0.70 mm. 



Remarks — As above mentioned, this is, in my opinion, the only as yet 

 known species of the genus. As regards the supposed new species described by 

 MM. Giard and Bonnier, and kindly dedicated to the present author, the only 

 distinguishing character given is the smaller number and comparatively greater 

 size of the ova contained in the marsupial cavities; but this is simply due to the 

 circumstance that the^specimen examined was of rather small size, in which case 

 the ova cannot of course be so numerous as in larger specimens, and must 

 also naturally appear of greater size in relation to the parent animal. 

 The other apparent differences, relating to the structure of the antennae, oral 

 parts, and incubatory plates, evidently are due to an imperfect examination. It 

 is, indeed, very difficult to get any correct idea of these parts without a^very 

 careful dissection and preparation, and such a close examination could not, as 

 above stated, be instituted by the said authors. As to the incubatory plates, MM. 

 Giard and Bonnier say that they have found them to be of essentially the 

 same structure as in^ Dajus mysidis. and they are also thus represented in 

 one of the detail-figures given. The fact is, however, that in the present genus 

 these plates, both as to form and number, are very different from those in 

 Dajus, and much more resembling those in Notophryxus. As in that genus, only 

 a single pair~of such plates are developed in front, to close the anterior open- 

 ing leading to the marsupial cavities, and these plates in this case too, 

 issue fronT the bases of the foremost pair of legs, the next succeeding legs 

 having no traces of plates at their bases. The above-named plates (see the 



