328 Mr. R. V. Chamberlin on new 



XXXVIII. — New Chilopods of the Genus Mecistocephalus. 

 By Ralph V. Chamberlin, Cambridge, Mass., U.S.A. 



[Plates IX.-XIL] 



Mecistocephalus celebensis, sp. n. 

 (PI. IX. figs. 1-9.) 



Body fulvous to light brown, without darker markings or 

 mottling. Head and prehensorial segment chestnut. An- 

 tennae light chestnut. Legs fulvous. 



Head nearly 1*75 times longer than wide. Sides straight 

 and only slightly converging, subparallel from frontal suture 

 back to the beginning of the more abrupt posterior nar- 

 rowing. Caudal margin truncate, wide. Anterior margin 

 straight, less angularly produced forward than in cephalotes 

 (PI. IX. fig. 1). No non-areolate chitinous spots in front of 

 paired clypeal area--. 



Labrum suggesting that of M. cephalotes, but the median 

 piece somewhat broader, less overlapped toward caudal end, 

 and the lateral pieces incurving at mesal ends (c/. PI. IX. 

 figs. 2 & 10). The free margin of each lateral piece incurves 

 more at outer end, where also the fringe of hairs is exposed 

 for a considerable distance, whereas this is wholly covered 

 in cephalotes and related forms. 



Mandible with twelve pectinate lamellae, of which the last 

 two are successively much reduced in length and are more 

 membranous (cf. PI. IX. fig. 4). First lamella with seven 

 uniform teeth, these stouter than those of the other two 

 lamellae (PL IX. fig. 5j. Teeth of ordinary lamellae long at 

 distal end, but from near middle of lamella proximad 

 strongly reduced (PI. IX. fig. 6). A median lamella with 

 thirty-seven or thirty-eight teeth. 



Coxosteruum of second maxillae with posterior angles 

 divergent, acute. Segmental pore large, subcircular. Ectal 

 angles of coxae of first maxillae scarcely produced, sub- 

 rectangular or but slightly acute (PI. IX. fig. 3). 



Exposed part of presternum 1'36 times wider than long. 

 Anterior border of presternum with the usual two rounded 

 teeth. Femuroid with two teeth, both of which are blunt, 

 the distal one the stouter. Two next joints each with a 

 rounded tooth, of which that of the second is obviously 

 stouter. Claw with a small but distinct tooth at base above 

 the ordinary protuberance (PI. IX. fig. 7). 



