]\[r. J. N. llalbcrt on In'tih nijdrachnida. 5 



MOMONIA*, g-cii. nov. 



Diagnosis of Genus. — An llydiaclmid of the family TIy;^ro- 

 batidaj (Kiaincr, Wolcott, &c.), with a highly chitiuizcd 

 intoguniciit modified into chitiiious phitcs. In shape re- 

 sembling the genus Midca, with a convex dorsal area separated 

 i'rom a larger ventral field by a groove in which are a number 

 of paired gland- openings. Epimeral groups close together, 

 occupying most of the underside of the body. Genital 

 area situated between the fourth epimera, flanked on each 

 side by a triangular plate, in which are imbedded three 

 genital suckers of the IJygrohates type. Palps with the 

 penultimate segment angularly swollen on the ventral 

 surface and armed with two stout chitinous teeth; fifth 

 segment ending in an exceedingly fine point. First pair of 

 legs modified, the terminal segment deeply excavated on its 

 upper margin, with a broad-shanked bifid claw articulating 

 deeply in the segment, and, in the type species, with a 

 terminal membrane. The three posterior pairs of legs are 

 provided with swimming-hairs. 



It will be Seen from this short diagnosis that the genus 

 Momonia possesses a very anomalous combination of characters 

 which renders the placing of it in a satisfactory position in 

 the Hydrachnid series a matter of some difKculty. On the 

 whole, however, it shows afKnities with the genera Midea, 

 Mideopsis, &c., and it seems to me that it should be placed 

 in an intermediate position between these genera and the 

 Hi/grohates group. 



Momonia falcipal pis f, sp. n. 

 (PI. II. figs. 1-4.) 



Male. — Body slightly longer than broad, evenly rounded 

 posteriorly, and narrowed towards the front niai-gin, where 

 there are two hair-papillae. Seen from the side the dorsal 

 outline is moderately convex and the ventral surface flat over 

 the cpimeral area; thickness of the body dorso-ventrally 

 about three fifths of the total lengtli. Integument highly 

 chitinized, with a dorsal groove running round, close to the 

 body-margin ; in this groove are placed at least six pairs of 



* M(imoiiia, or Mumonix, the ancient Latin name of the province of 

 Mimster. This name has also been used by Mr. R. Lloyd Praej^er, 

 M.R.I. A., to indicate the group of plants with a southern range in Ireland 

 (see * Proceed. Royal Irish Academy,' vol. xxiv. 1902-1004). 



t The specific name is suggested by the shape of the terminal palp- 

 eegment. 



