448 Mr. Gilbert J. Arrow's Classification of 



the latter respect, by which he distinguishes R. munitus, 

 Casey's dimensions agree ahnost exactly with those of 

 Truqui's type. 



This species is therefore the proper type of Oileus. 

 Zang has rightly indicated the true species but without 

 knowing that Kaup had wrongly applied the name Sagit- 

 tarius to it and has so become involved in the confusion. 

 Passalus Sagittarius, Smith, of which no second specimen 

 is yet known, really belongs to Kuwert's group Petrejinae, 

 differing from the genus Petrejus in being flightless, and 

 having accordingly very short elytra fused together at the 

 suture and curvilinear at the sides. A similar form has 

 been described as Procuhdus inca by Zang and, although 

 the generic characters formidated from that species are 

 not all exhibited by Smith's insect, I think the two may 

 very well be associated together. The type of Procnlulus 

 Sagittarius is rather larger than that of P. inca, it has the 

 labrum arcuately excised along its whole width, so that 

 the angles are acute, as the clypeal ridges extend beyond 

 the front margin and are distinctly tuberculated both at 

 their extremities and a little before, and the median horn 

 is long, free, acutely pointed and without lateral out- 

 growths behind. 



The synonymy of Oileus is accordingly as follows : — 



Oileus, Kaup, Col. Hefte, 1869, p. 3, 

 Rimer, Kaup, Mouogr., App. p. 119. 



, Bates, Biol. Centr.-Amer. (2) ii, pp. 10 and 383. 



, Kuwert, Nov. Zool, 1897, p. 287. 



Rirnoricus, Kuwert, 1. c. 



rimator, Truqui, Rev. de Zool., 1857, p. 266. 



Sagittarius, Kaup (uec Smith). 



, Bates, 1. c. 



, Kuwert, 1. c. 



munitus, Casey, Ann. New York Acad., ix, 1897, p. 644, 



sargi, Kaup, 1. c. 



V. honcstus, Kuwert, 1. c. 



Kuwert's Rimor ridicuhis has been separated by Zang 

 as Goniger ridiciclus, Kuw., and for the second Oileus of 

 Kaup (i. e. hcros, Truqid) Zang has coined the new generic 

 name Nasoproculus. 



The differences which served Kuwert for the generic 

 separation of Oileus rimator, Truqui, and Sargi, Kaup, are 



