Stophyliuida of tlie Amazon Valley. 279 



punctured. Hind body much pointed towards the extre- 

 mity, the basal segments densely, moderately coai'sely, the 

 apical ones very finely punctured. Legs pale yellow. 

 Front tibiae slightly dilated towards the apex, and dis- 

 tinctly bisinuate externally. On the underside of the head, 

 at the base of the mouth, are two peculiar fine tubercles. 



Tapajos ; five specimens. 



Obs. — This species varies much in colour, some indi- 

 viduals being nearly black, and others reddish or yellow. 



I have dissected the terminal segments of one of these 

 specimens, with the hope of ascertaining it to be a male ; 

 but I am unable to say positively Avhether this is the case 

 or not ; for though I have found Avhat may possibly be the 

 jedeagus, yet it is so small and insignificant that I am by 

 no means sure it may not be merely a portion of some 

 dried internal tissue ; — this although I have examined it 

 with a very high power. 



7. Echiaster muticus, n. sp.? Infuscato-rufescens, ely- 

 trorum fascia basali, antennis pedibusque testaceis; opacus, 

 dense punctatus ; capite angusto, vertice elongato, subtus 

 mutico ; thorace minus elongato, latins bisulcato. Long, 

 corp. 2 lin. 



Tapajos ; two individuals. 



Obs. — These two specimens present no difference from 

 E. mamillatus, except the absence of the tubercles on the 

 underside of the head ; it is probable that this may be 

 merely a sexual character, the E. muticus being only the 

 other sex of E. mamillatus, in which case the species may 

 bear the name E. mamillatus. 



8. Echiaster tibialis, n. sp. Eufus, opacus, dense 

 punctatus, pedibus testaceis ; capite elongato, postice 

 angustato ; thorace minus elongato, latins bisulcato ; 

 tibiis anterioribus extus dilatatis. Long. corp. If lin. 



Antennae red, stout, as long as the head; joints 5 — 10 

 each transverse, and each slightly broader than its pre- 

 decessor; 11th joint short. Mandibles very slender, 

 rather short. Labrum distinctly quadridentate. Head 

 elongate, the sides narrowed, but not rounded from the 

 eyes to the neck ; the surface elevated in the middle, 

 densely and obscurely punctured, quite dull, reddish. 

 Thorax much narrower than the elytra, rather longer 

 than broad, the sides almost rounded ; the greatest width 



