33^ 



OX THE END08KELET0N OF THE HE.VD, THE AN- 

 TERIOR COX^, AND THE AXTERIOR COXAL 

 CAVITIES IN THE FAMILIES CARABID^ AND 

 CTCINDELTD^. (Colkoptera). 



By Thomas G. vSloane. 



i. Endoskeleton of head. 



In the CaiabicUt' and Cicindelicla^, there is a cliitinoiis endo- 

 skeleton, M'hich defines the buccal cavity behind. This endo- 

 skeleton has the form of a thin, narrow, median plate of chitin, 

 which gives off four slender supports, one from each angle; two 

 of these extend upwards, and attach themselves to the inner 

 side of the front behind the clypeus; and two extend downwards, 

 uniting with the submentum. The result is that the endoskeleton 

 has, roughly, the form of the figure 8, or of two arches (the upper 

 one inverted) united in the middle by a flat, somewhat quad- 

 rangular plate. The tesophagus passes through the lower arched 

 opening. The endoskeleton, on its anterior side, helps to support 

 the muscles of the mouth-parts; especially, in the case of the 

 lower arch, those of the maxilhe and labium. Attention is now 

 drawn to the difference in the manner in which the lower sup- 

 ports of the endoskeleton unite with the exoskeleton in the 

 Carabidse and Cicindelidne. 



Carabidie. — Lower supports attached wholly to the submentum, 

 but not to the lobes of the mentum. 



6*^c^nc/e/^o?<:c.— Lower supports attached to the submentum, and 

 also to the lobes of the mentum, these being raised inwards to 

 meet them. 



The endoskeleton of the head in insects has been very fully 

 treated by A. Berlese ("Gli Insetti,"' chapter on 'Endoscheleton 

 del Capo'). I am indebted to Mr. R. J. Tillyard for this in- 

 formation, but I have not had an opportunity of consulting this 



