Mr. G. Newport on some new Genera of Myi-iapoda. 499 



ment, J. E, Gray, Esq., has kindly permitted me to describe and 

 arrange, I have since found two other species, both new to science, 

 one of which was brought from India by — Elliot, Esq., but the lo- 

 cality of the other is unknown. The genus I am now about to pro- 

 jjose will thus include five species, agreeing most accurately in their 

 generic characters. They are all of them foreign to this country. 

 The only native species which at all approaches to Mecistocephalus 

 is the Geophilus longicornis of Leach, supposed by i\I. Gen'ais to be 

 Scolopendra electrica of Linnaeus, which constitutes Leach's second 

 section of Geophilus. This I propose to separate as a distinct sub- 

 genus, by the name of Necrophlaophagus , although its characters are 

 not so distinctly marked as in the preceding. The name proposed 

 for it is derived from its being mostly found under rotten wood, or 

 under the rotten bark of trees. 



Before I proceed to characterize these genera, it may be well to 

 remark, that the construction of the head in these, as compared with 

 the other Geophili and the Scolopendra, seems to throw much light 

 on the number of parts which are included in this division of the 

 body in the higher Articulata, and on the manner in which these 

 l^arts are united ; and although I do not intend on the present occa- 

 sion to enter on the consideration of these structures, which I pro- 

 pose to do hereafter, it is necessary to state that I regard the head 

 of the Chilopoda as formed of two compound moveable portions, the 

 anterior of which, bearing the antennae, I shall designate \he frontal 

 segment ; and the posterior, which gives attachment to the large forci- 

 pated foot-jaws, which I regard as the analogues of the mandibles of 

 insects, I shall call the basilar segment. Posterior to these there is 

 a third part, which, although perfectly distinct in all the Geophilidce, 

 is united to the basilar in the Sculopendroi and higher genera of this 

 order, forming a kind of cephalo-thorax or cephalo-prothorax. This 

 I shall consider the second or suh-basilar segment. 



It is on characters derived from these parts that I now propose 

 to establish the genera. 



Class MYRIAPODA. 

 Order 1. Chilopoda. 

 Family Geophilid.*;, Leach. 

 Section A. Geophili maxillares, Gervais. 

 Genus Mecistocephalus* , Newport. 

 Characters. — Frontal segment very narrow, elongated, four-sided, 

 more than twice as long as broad, antennae inserted on the frontal 

 margin, subapproximated, three times as long as the frontal segment ; 

 joints obconic, rather elongated, slightly hair}^ ; basilar segment qua- 

 drate, very short, and much narrower than the frontal, almost atro- 

 phied on the dorsal surface ; labium and inferior surface of the basilar 

 segment very large, quadrate, extending backwards beneath the sub- 

 basilar segment, with its anterior margin slightly excavated ; mandi- 

 bles enlarged, straightened, and projecting, but curved and pointed 

 * From fiTjKitTTog, longest, and Ks(pa'h^, head. 



