1909] Geophilidae and Lith?bndae 181 



II. Geophilus atopleurus sp. nov. PI. XXIV, figs, i, 2, 3. 



Strongly attenuated cephalad, caudad more abruptly narrowed. 



Light, .somewhat olivaceous, brown. Head, prehensorial feet and 

 antennae orange. Legs pale yellow. Venter a little paler than the 

 dorsum. 



Articles of the antennae very graduallv decreasing in length distad, 

 the ultimate shorter than the two preceding together. 



Cephalic plate a little longer than broad (12:11). Lateral halves 

 of anterior margin running cephalad. to meet at an angle on the mesal 

 line. Back of each anterior angle the side is first weakly convex and 

 the concave at end of frontal suture; back of this the sides are nearlv 

 straight and parallel, caudally rounding in to the wide posterior mar- 

 gin which is weakly concave. Head marked in front of the posterior 

 margin with two diverging sulci. Frontal plate discrete. Prebasal 

 plate exposed mesally. Basal plate 2.4 times wider than mesal length. 



Claws of prehensorial feet when closed attaining the front margin 

 of cephalic plate or but little short of it. Tooth on claw very obscure 

 or obsolete, no trace of one on other joints. Presternum and femora 

 punctate. 



Dorsal scuta sharply impressed with the usual two sulci, which lie 

 rather close to the median line, some with a more indistinct median 

 sulcus. Anterior prescuta short, becoming very long at and caudad 

 of the middle; not much shortened on posterior segments, long. 



First spiracle large, circular or a Httle obliquely elongate; others 

 circular from the second caudad decreasing gradually but not strongly. 



A median process on posterior margin of the second to sixteenth 

 ventral plates fitting into a corresponding pit or excavation in anterior 

 margin of succeeding plate. Ventral pores in a transverse band a little 

 in front of the posterior margin. Sterna with a median longitudinal 

 sulcus which in anterior segments is short and sharplv impressed 

 but on posterior segments extends over full length of scuta and is 

 crossed in some by one or more rather indefinite sulci. 



Last ventral plate wide; anterior angles rounded; sides somewhat 

 excurved and strongly converging to the conspicuously rounded pos- 

 terior margin. Pleurae moderately inflated; each with about eighteen 

 pores on each side arranged along and partly beneath the ventral plate 

 and along the presterna and with four or five on dorsal side near and 

 beneath the dorsal plate ; on the ventral surface caudo-laterad from 

 the posterior pores a peculiar chitinous mark in a position in .some 

 species occupied by an isolated pore. 



Last legs a little enlarged; armed with a large claw. 



Anal pores distinct. 



Pairs of legs 00 ( 9 ) . 



Length 39 mm. Width 1.4 mm. Length of antennae 3 mm. 



Locality — Raleigh, North Carolina (Brimley, 1901). 



Belonging in the mordax group of species with virginiensis 

 Boll, and louisianae Brol. 



