342 exdoskp:leion of head, i-c, iN" cARAfiiD.?:, itc. 



uniting on each side with point of prosteinum inward from apex; 

 anterior coxye contiguous. Xote. — In the genus Oviophron, the 

 mesosternum has, on each side of the apex, a small cavity, which 

 helps to support the anterior coxa.* 



(2). Open anterior coxal cavities. Genus Pamhorus. Anterior 

 coxal cavities open behind; inner opening single; peduncle of 

 body supported by the point of the prosternum; no intercoxal 

 declivity or intercoxal plate present; intercoxal partition greatly 

 reduced, inner side narrow, oblique; anterior coxa> contiguous. 

 This is the form in the Tribes Trachypachini, Carabini, Nebriini, 

 Pamborini, and Hiletini. Xofc. — In the Tribes with open coxal 

 cavities, the mesosternum is keeled in the middle, and, on each 

 side of the keel, there is a small fossa to help in supporting the 

 anterior coxa. 



The usually accepted view is, that open anterior coxte are the 

 primitive form in the family Carabidte, but Lameere has pub- 

 lished his belief that the original Carabidai had closed anterior 

 coxai.t As far as I can interpret the evidence, it does not sup- 

 port the current view that the open anterior coxal cavities are 

 primitive. Some facts which have weighed with me are. (l)The 

 closed form is that of the family Cicindelidjc, and is, therefore, 

 very ancient in that it antedates the differentiation of the Cara- 

 bidte and Cicindelidye from the prototypic stem from ^^■hich both 

 were derived. (2) The form of the juxtacoxal parts of the pro 

 sternum in Omophrott suggests to me a modification by reduction 

 fiom the ordinary closed form. (3) In the open form of coxal 

 cavities, the process of reduction seems carried still further. 

 J^ote. — I cannot think that the supporting fossae of the meso- 

 sternum are the primitive Carabid-form, seeing that similar fossa' 

 are found in the genus Flati/chila, in the Cicindelidtt^, where they 

 are not the original type. 



* Cf. Dr. Walther Horn, &p. cit., pp. 17 and 19, for remarks on 

 Omophron; and Taf. 4, fig. 29, for a drawing of the prothorax showing the 

 basal socket and coxal cavities in Omophron. 



t Ann. Soc. Ent. Belg., 1900, p.37o. Quoted by Dr. Horn, /.c, p. 69. 

 I have not seen Lameere's work, which I know only from Dr. Horn's 

 citation. 



