206 LAMELLICOENIA. 



49. Lachnosterna segregans. 



L. molopice affinissima, differt solum statura minore, clypeo transverso utrinque late rotundato, margine antico 



sat late reflexo, medio distincte sinuato, et antennis c? longissime clavatis. 

 Long. 14-17 millim. 



Hob. Mexico, Ciudad in Durango (Hoge). Three examples, all males. 



Kesembles the smaller examples of L. molopia, chestnut-coloured and glabrous above, 

 fulvo-testaceous beneath ; the elytra more strongly punctate-rugulose. The form of 

 the clypeus is different, being short, rounded on each side, and rather strongly sinuate 

 anteriorly, instead of being rather long and obtusely trapezoidal as in L. molopia. The 

 callosities on the middle ventral segments are feeble or obsolete ; the sixth segment 

 (male) is formed precisely as in the male variety of L. molopia. The pygidium is coarsely 

 rugose-punctate as in L. molopia ; but the thorax differs in wanting the two large 

 postero-discoidal fovea?. The lower tooth of the tarsal claws is very small, outstanding, 

 and situated about the middle of the claw. The antennal club is greatly elongated, 

 and longer than the rest of the joints taken together. 



50. Lachnosterna divertens. 



L. molopice quam proximo affinis ; differt solum statura angustiore (anguste oblonga sive cylindrica), clypeo 



adhuc magis elongato, semiovato, perparum vel nullomodo sinuato et antennis longissime clavatis. 

 Long. 17 millim. 



Hab. Mexico, Ciudad and Kefugio in Durango (Hoge). 



Three examples, males. The chief character which necessitates the separation of 

 this form from L. molopia is (as in L. segregans) the great length of the antennal club 

 in the male. It differs from both these species in its narrow, cylindrical form, and 

 in the shape of the clypeus — narrowed anteriorly as in L. molopia, but having 

 no trace of angles, and gradually rounded to the front and feebly or not at all 

 notched on its anterior edge, which is scarcely reflexed ; both clypeus and forehead are 

 more minutely and densely punctured than in L. molopia. The ventral callosities are 

 feeble or entirely obsolete. The pygidium offers no difference, and the sixth ventral 

 segment is formed as in the male variety of L. molopia. The tooth of the claw is short 

 as in L. molopia, but situated a little higher (i. e. towards the apex) than the middle 

 of the claw ; it varies a little in position, as it does in L. molopia. 



The antennal club varies in length, but in the examples in which it is shortest it 

 equals in length all the remaining joints together. Judging from this and other 

 evidences of variability or plasticity in this interesting group. I think that we have 

 here a case of an incipient species in process of segregation. 



51. Lachnosterna setipennis. 



L. molopice quoque affinis, sed differt statura angustiore, cylindrica, elytrisque toto griseo-setosis, setis erectis 

 parum densis. Nigra vel castaneo-fusca, minus nitida ; clypeo semicirculari margineque leviter reflexo 



