38 U. S. p. R. R. EXP. AND SURVEYS ZOOLOGY 47TH PARALLEL. 
appearance, resembles G. canaliculatus , but the mentum is of a different form, and on compari- 
son many other differences may be seen. From C. Schaumii, Lec. (Proc. Acad. Nat. Sc. 6, 231) 
it differs by the smaller size, less rounded sides, but more acute angles of the thorax, and by 
the posterior angles being separated by a small but deep oblique impression ; near the margin 
of the elytra may be seen a few whitish tranverse undulated lines. 
Tryssus Er. 
T? comahis, nitidus, capite obscuro, confluenter punctate, clypeo concavo rotundato, fortiter 
marginato, thorace luteo-ferrugineo, marginibus longissime flavo-pilosis, lateribus valde rotun- 
datis, angulis anticis acutis, confertim punctato, versus latera utrinque foveato, elytris piceo- 
testaceis, ad marginem flavo-pilosis, obsolete punctatis, stria suturali profunde exarata, propy- 
gidio dense punctato, pubescente, pygidio parce piloso et punctulato, nitido : subtus ferrugi- 
neus, femoribus et pectore longe pilosis, abdomine glabro, articulo sexto postice parce fimbriate. 
Long. "68. 
One specimen, Sacramento, Mr. Wittick. This is the first appearance of the group Macro- 
phyllidae in America ; it differs from the genuine Melolonthidae by the segments of the abdo- 
men being separate, with distinct sutures. On account of the 9-jointed antennae with three 
jointed club, I have referred it to a genus constructed by Erichson (Ins. Deutchl.) for some 
South African species ; the ungues are cleft, (as required by his description,) each division being 
broad and acute, the inferior one is a little short ; the tarsi are longer than the tibite, and the 
last joint is armed with a small tooth beneath, near the tip. The labrum is large and emargi- 
nate, and the epimera of the metathorax are broad. 
DiPLOTAxis Kirby. 
D. brevicolUs, ferrugineo-picea, oblonga nitida, capite confertim punctato, sutura frontali 
distincta, clypeo late emarginato, margine anguste reflexo, thorace latitudine triple breviore, 
punctato, antrorsum angustato^ antice transversim impresso, ad angulos posticos foveatim exca- 
vate elytris serie suturali, quatuor per paria approximatis, quinqueque externis punctatis, 
interstitiis inter paria et suturam disperse punctatis ; pygidio grosse punctato. Long. •45. 
Steilacoom, Washington Territory ; G-eorge Gibbs, esq. One specimen. 
D. subangulata, oblonga, nigra nitida, clypeo confertim punctato marginato, lateribus obli- 
quis ad apicem late truncate, thorace sub-hexagene, sat punctate, latitudine plus sesqui brevi- 
ore antice angustiore, lateribus medio obtuse angulatis et rotundatis, angulis posticis obtusis 
vix rotundatis, elytris oblongis thorace latioribus, punctis minus subtilibus seriatim digestis 
(seriebus internis cenfusis); pygidio confluenter grosse punctato. Long. •34. 
Oregon. Similar in appearance to many ethers, but readily known by the characters given. 
DiCHELoNYCHA Kirby. 
D. valida, elengata, nigre picea, supra parce subtus densius albepubescens, thorace brevi 
hexagono, inaequaliter grosse punctate vage impresso, modice canaliculate, elytris confertim 
rugose punctatis, fusco a3neis viridi tinctis, margine, antennis pedibusque testaceis. Long. "55. 
One specimen ; San Francisco, Mr. Child. Larger than any other species known to me. 
The New Mexican D. sulcata, Lec, (report of Captain Pope's expedition,) has the thorax 
