CYRIONYX. 189 
the other, and no particular value can be placed on the amount of development of the 
prosternal sulcus, the sinuation of the base of the prothorax, and the contiguity or 
separation of the tarsal claws, they are here all placed under Cyrionyx. The following 
are their essential characters :-— 
Mandibles toothed within ; rostrum arcuate, as long as, or longer than, the head and prothorax, with obliquely 
descending scrobes; prothorax bisinuate or subtruncate at the base, without ocular lobes; scutellum 
subtriangular or trapezoidal; elytra much wider than the prothorax, subtriangular; prosternum 
unarmed in ¢, the median sulcus (deep, shallow, or almost wanting) limited posteriorly by the 
contiguous or narrowly separated anterior coxe, the other coxe distant; femora each with an acute 
tooth, feebly clavate ; anterior tarsi similarly formed in the two sexes ; tarsal claws free or subconnate ; ; 
body more or less clothed with narrow scales. 
Thus defined, Cyrionyx (in its extended sense) may be separated from Optatus, 
Telemus *, and Eurypages, all of which have the anterior tarsi greatly dilated and 
hairy in the males, Zelemus, moreover, having the femora clavate, as in Lydamis. 
Some of the species might easily be mistaken for Conotracheli. 
a. Prosternal sulcus deep; prothorax (except in C. cavirostris) more or less 
sinuate at the base. 
a‘, Elytra with the alternate interstices completely or interruptedly costate. 
a, Humeri prominent or subangularly dilated ; anterior coxe contiguous 
or subcontiguous. 
a®, Tarsal claws divergent. . . . . 6 2 «© «© «© © «© « «© « « Species 1. 
}°®. Tarsal claws contiguous at the base. 
a‘. Third and fifth elytral interstices interruptedly costate and each 
with a hump-like elevation below the base; rostrum comparatively 
short . Se ee ee eee . Species 2. 
&*. Third and fifth elytral interstices uninterruptedly costate, the 
third only with a hump below the base; rostrum very long 
and slender . 1. 6 2 6 ee ww ee ew ew we ww ee Species 3. 
. The alternate interstices simply costate . . . . - » « Species 4, 5. 
b. Humeri not prominent ; anterior coxe well-separated ; tarsal claws free, 
c’. Prothorax without prominence on the disc . . . . . 4. . . Species 6. 
d°®. Prothorax with a large prominence at middle of disc. . . . . . Species 7. 
', Elytra and prothorax with large setigerous prominences on the disc, the 
median one on the third elytral interstice long and acutely produced 
posteriorly, the humeri sharp; anterior coxe well separated ; tarsal 
claws divergent . . . . © ee ee . . . Species 8. 
'| Elytra and prothorax with smaller prominences on the dise, the humeri 
obtuse ; anterior tarsi contiguous ; tarsal claws contiguous at base . . Species 9, 
a’. paihie faintly costate down the middle of each interstice. . 
. Rostrum long, not sulcate beneath ; tarsal claws contiguous at base. Species 10. 
* The type of this genus, Centrinus cestrotus, Boh., has the femora strongly dentate, not ‘ mutic,” as stated” 
by Pascoe. 
