4 ADEPHAGA. 
This little mite is readily distinguished from NV. gracilipes by the polished upper 
surface, quite destitute of punctuation on the wing-cases, as well as by the more uni- 
form colour. It appears also to be slightly smaller, and to have the antenne a little 
shorter. It is extremely similar to the Australian WV. /evigatus, but is of more depressed 
form, and, moreover, is considerably smaller. 
MESONOTERUS. 
Pronotero quoad faciem similis, inter eum et Noterwm quoad pedes anteriores locandus. Caput magnum; antenne 
mediocres, articulis intermediis secundum sexum plus minusve leviter incrassatis ; palpi labiales articulo 
ultimo valde dilatato, minute emarginato ; mentum in medio angustissime denticulatum ; prosterni processus 
planus, subovalis; coxarum posteriorum laminis internis elevatis, apicibus acuminatis, parum prolongatis, 
angulis absque setis; acetabula inter se perparum distantia. Tibie anteriores graciles, angulo externo 
obsoleto, brevissime ciliato, ad apicem calcari tenui sed sat elongato, parum curvato, armate. Pedes 
natatorii fere graciles, femoribus apice externo rotundato, haud penicillato, tibiis intus densissime, extus 
parcius ciliatis, calcaribus elongatis tenuissimis, tarsis omnino gracilibus, quam tibize paulo longioribus. 
The insect for which this genus is proposed has quite the appearance of the South- 
American Pronoterus, and connects that genus quite evidently with the Noterini. 
Mesonoterus differs from it, however, by the lighter structure of the front legs, which 
resemble those of Noterus in form, but are more slender; and the swimming-legs also 
are more slender and less powerful. Although there is no pencil of sete at the 
extremity of the hind femora, there are yet two or three very fine elongate hairs. 
1. Mesonoterus levicollis. (Tab. I. fig. 2.) 
Ovalis, transverse sat convexus, postice acuminatus, testaceus, elytris livide brunneis, irregulariter sat crebre 
et sat fortiter punctatis, punctis suturam versus desinentibus. 
Long. 17 lin. 
Hab. GuatEMALA, Paso Antonio, 400 feet (Champion). 
Antenne about as long as head and thorax, with the intermediate joints broader 
than the basal and the two apical joints. Head rather elongate, without sculpture, 
shining. Thorax strongly transverse, almost entirely without punctuation, the punc- 
tures near the front margin being obsolete. Elytra of darker colour and less shining 
than the head and thorax, with numerous irregularly scattered rather large punctures, 
which are wanting along the suture. Under surface almost impunctate, there being a 
few fine punctures on the middle portion of the metasternum, and still fewer on the 
elevated lamine of the hind coxe; the lateral portions of the metasternum, hind coxe, 
and ventral segments are dull and finely coriaceous. 
The male has the antenne broader than the female, and the basal joint of the front 
and middle tarsi greatly incrassate. The female has the last ventral segment at the 
extremity folded and compressed so as to form a very prominent plica; in each sex the 
apex of the body appears mucronate, owing to the projection of the cedeagus or of the 
ovipositor. 
