MISCELLANEA RHYNCHOTALIA. 281 



Hob. Ecuador, Guayaquil (coUn. Montandon). 

 Allied to H. caraiba, Guerin, but separable by the proportions 

 of the antennae, &c. 



• ^ Hydrometra naiades, nom. nov. 



= H. mensor, Champion, nee White. 



Besides unimportant colour differences. Champion mentions 

 " anteocular portion (of head) about twice as long as the post- 

 ocular portion," while White describes H. mensor as "anteocular 

 part not quite once and a half as long." As this proportion of 

 the head is one of the most important characters in the specific 

 differentiation of Hydrometra, it is impossible, at present at least, 

 to retain the name mensor for Champion's species. White's type 

 is unfortunately lost or destroyed, as is also that of H. metator. 



Rheumatometra, gen. nov. 



Allied to Kallistometra, Kirk., and Halobatopsis, Bianchi, but 

 differing by the proportions of the antennae, legs, &c. 



Suboval ; antennae short, subequal to the pronotum in the winged 

 form ; first segment shorter than the other three together, fourth 

 fusiform, one-fourth longer than the third. Apical segment of anterior 

 tarsi three or fourth times as long as the basal ; posterior femora 

 a little longer than tibiae and tarsi together ; intermediate legs very 

 long, tibiae longer than femora, which are a trifle longer than tarsi. 



Macropterous form : Pronotum slightly convex, rounded posteriorly. 

 Elytra long, extending far beyond apex of abdomen. 



Apterous form : Pronotum short, transverse. 



R. philarete, sp. nov.* 

 Velvety black ; base of first segment of antennae, a large spot in 

 the middle of the anterior lobe of pronotum, lateral margins of the 

 nota, the connexivum above, coxae (in part), &c., bright luteo-fiavous. 

 Male anterior femora and tibiae strongly curved and somewhat in- 

 crassate. Female anterior femora and tibiae only slightly, if at all, 

 curved or iucrassate. Long, (to apex of abdomen), 3' 2|- mill., $ 

 il mill. ; lat. <? H mill., ? 2-2^ mill. ; long, to apex of elytra, ? 

 e^mih. 



Hab. Australia, Victoria, Alexandria (collns. Montandon 

 and Kirkaldy). 



MiCROVELIA STELLATA, Sp. UOV. 



Apparently allied to M. albonotata, Champion, but that species 

 is described as not having the vertex longitudinally sulculate, and 

 the colouring is somewhat different. 



Elongate. Black ; basal half of first antenual segment, basal 

 three-fourths of femora pale flavescent. Anterior margin of pronotum 

 (entirely) fulvous. Antennae, elytra, and legs dark sienna-brown, the 



'''■ I have a revision of the Gerridse in progress, where these and other 

 forms will be described in more detail. 



