232 



SEEEICOEXIA. 



very thin, ciliate on its edges and sparsely hairy on its flat sides ; the inner lobe is 

 shorter, ribbon-like, slender at the base, and apparently not ciliate. In lieu of palpi the 

 maxillee have, arising at their base, two simple stems like those of the mentum. 



The entire structure, when dry, is extremely delicate and fragile, the ribbon-like 

 appendage of the mentum much contorted, but when placed in water the stems become 

 swollen, and the appearance then is much like a spongy mass. It is therefore 

 extremely difficult to realize the exact structure from these 

 two causes; but the accompanying figure will give a fair 

 idea of it. The figure represents the left side of the 

 mentum as seen from below, the maxilla removed from that 

 side. The maxilla is that of the right side in its normal 

 position, the half of the mentum removed in front, although 

 in nature the palpar organs are turned more outwardly. 



The mandible presents nothing unusual. It is stout, 

 truncate at the tip, the lower edge prolonged in a lamina 

 which partly covers the delicate parts beneath. 



When the head is deflexed the mouth-parts rest in the 

 concavity of the prosternum, which is smooth at the middle and finely pubescent at 

 the sides. 



While I do not maintain that the sketch is perfectly accurate in all details, it 

 certainly fairly represents what I have been able to make out, and should any one be 

 fortunate enough to possess the material to repeat the experiment of elucidating this 

 complex arrangement he will be very willing to excuse any defects of this attempt. 



l. Cladus maxillaris. 



Cladus maxillaris, de Bonv. Mon. p. 433, t. 21. fig. 9 1 . 



Hob. Mexico, Teapa (coll. Chevrolat 1 ); Panama, Bugaba, Vol can de Chiriqui, David 

 (Champidn). — Guiana, Cayenne 1 . 



The facies of this insect is almost exactly that of Fornax affinis. 

 De Bouvooloir remarks that either the first or last of these localities is probably 

 incorrect. As our localities are intermediate it is probable that both are correct. 



PLESIOFORNAX. 



Plesiofornax , de Bonvouloir, Mon. des Eucnemides, p. 460 (1870). 



As the name indicates, this genus is very close to Fornax. The essential difference 

 between the two is found in the propleural structure, Fornax having the antennal 

 groove more or less sharply limited internally by the edge of the propleural triangle, 

 while in the present genus no such character is evident, and the groove is indicated by 

 a smooth depression, which may itself be very indistinct. As a general rule the claws 



