232 Mr. D. Slui^ Cuidrihutions to the 



extremity of the Ttli segment, beneatli ; tliis noteli is of a 

 peculiar slia})e, l)eing somcAvliat conti-acted at its entrance, 

 in front of it the segment is a little impressed ; tlie 6th 

 segment has the hind margin broadly but slightly emar- 

 ginate. 



Ega ; three male specimens ; also one from Santarem, 

 but I am not sure that this indication of locality is correct. 



I have also from Ega two female individuals of a 

 Latlirohhun, which I had at first described imder the name 

 ofX. qumlraticolle, but on re-examination I think it highly 

 probable that they may be females of L. ojxilcscens, from 

 Avhich they dilfer by being much larger and broader, their 

 length being 5g lin. I have ascertained by dissection of 

 one of them that it is a female ; the ventral plate of the 

 7 th segment is not rounded in the middle, but is very 

 slightly emai'ginate ; the dorsal lobe of the 8tli segment is 

 very compressed at the extremity, so that it appears to 

 form a sharp longitudinal carina. 



3. Latlirohium dccisum, n. sp. L. opalcsccnti omnino 

 similis, notis scxualibus tantum differt. 



Mas: abdomine segmento 1° ventrali apice medio pro- 

 funde, sat late semicircularitcr exciso : segmento 6" late 

 profundcque longitudinaliter impresso, apice medio emar- 

 ginato, utrinque angulatim producto. 



Tapajos ; a single male. 



I am imable to find any characters except the sexual 

 ones to distinguish this species from L. ojialesccns, but 

 these are very marked and important. The notch of the 

 7th segment is narroAver and deeper, not contracted at the 

 entry. The 6tli segment has a broad and deep longitu- 

 dinal impression along the middle ; the sides of this impres- 

 sion are remarkably abruptly defined, and jiroject beyond 

 the hind margin, so as to form an acute angle. 



I have also, fi-om the same locality, a female individual, 

 which I believe to be the other sex of this species ; it is 

 about the same size as the male ; it has the hind margin 

 of the 7th segment beneath slightly emarginate in the 

 middle ; it differs from the female described as that of L. 

 opalescens by its much smaller size, and by the shorter and 

 much less laterally compressed dorsal lobe of the 8th seg- 

 ment. 



4. Latltrohium puncticeps, n. $,\). Piceo-rufum, niti- 

 dum, antennis pedibusque rufo-testaceis ; ca]iite subopaco. 



