212 Mr. G, R. Waterhouse's Description of 



Disphericus Gambianus. (Plate XII. fig. 2.) 



Disph. ater, nitidus ; thorace globoso, dorso canaliculate ; elytris 

 ovatis, valde convexis, profunde striatis, striis punctatis, 

 interstitiis convexis. 



Long, coi-p. lin. 8, lat. 3. 



Habitat in Gambia Africse tropic. Mus. Dom. Melly. 



Plate XII. fig. 2. Disphericus Gambianus, slightly magnified. 

 2 a, front view of the head ; 2 b, fore leg. 



This insect presents such a curious combination of characters 

 that I find it difficult to satisfy myself as to the situation in which 

 it should be placed among the Carahidce. Mr. Melly considers it 

 allied to Cychrus, in which opinion I coincide to a certain degree, 

 but it differs from the species of that genus in several important 

 particulars ; in the first place, the anterior tibiae are deeply notched 

 on the inner side, and this notch is far removed from the apex of 

 the tibiae, the tarsi are stouter and the anterior pair are rather dis- 

 tinctly dilated in the male. The head and mandibles, although 

 long, are nevertheless shorter than in Cychrus; the mandibles 

 mor^ curved, stouter, the point is more obtuse as well as the 

 internal teeth, and the inner portion does not appear to be mem- 

 branous and furnished with a series of short bristles as in the 

 species of that genus. The labrum is short, whilst in Cychrus it 

 is long, and the same difference is observable in the mentum : the 

 palpi are shorter and the terminal joint is more truly triangular. 

 In the form of the thorax, and in many other parts of its struc- 

 ture, the present insect differs much from Cychrus. In the form 

 of the head it is intermediate between that genus and Eurysoma 

 (or Brachygnathus) ; its antennae more nearly resemble those of 

 the latter genus, being stout, but are proportionately longer. In 

 the structure of the anterior tibiae, and in the incrassated form of 

 the anterior femora, I find characters in which the present genus 

 approaches very near to Apotomus, which has the same peduncu- 

 lated thorax. On the whole I think this new genus should be 

 placed between Apotomus and a group of Carahidis, which may 

 include Tefflus, Pamhorus, Eurysoma, Panagceus, and some other 

 genera, closely allied to which on the one hand is Cychrus, and on 

 the other Carabus. These insects, with their large palpi, appear 

 to me to be all nearly allied, though by some naturalists they are 

 separated ; I believe chiefly owing to the circumstance of the 

 anterior tibiae being notched internally in some and not in others. 

 We find, however, on examination, that the difference consists 



