496 bulletin: museum of comparative zoology. 



TiDOPS SIM us, sp. nov. 



General color ochraceous. Head and prosternum dark reddish 

 brown or ferruginous. Legs yellow. 



Head with median sulci showing as two short parallel lines across 

 caudal border. Head differing slightly in width anteriorly and pos- 

 teriorly; anterior margin widely semicircular; caudal margin sub- 

 truncate or but slightly excurved. 



Antennae flattened, composed of thirteen articles of which the first 

 two, three, or four are very sparsely hirsute, the others becoming 

 gradually more and more densely and finely clothed with short straight 

 hairs of the type usual in the family. 



Claws of prehensors dwarfed. None of the articles of prehensors 

 armed within. 



Prosternum with two deep and continuous submedian longitudinal 

 sulci. Anterior margin bearing two large, cylindrical, distally rounded 

 teeth or dentiform processes. 



Transverse sulcus of first dorsal plate strongly bent back in an angle 

 at middle, the vertex lying in a rather deep depression or pit; sulcus 

 wholly free from the cephalic plate. Longitudinal sulci subparallel or 

 a little converging cephalad from the caudal margin to about two thirds 

 the distance to the transverse sulcus where each bifurcates, sending its 

 mesal branch to meet its mate at the angle of the transverse sulcus and 

 its outer branch ectocephalad to meet the transverse sulcus farther 

 laterad. Dorsal plates from the second one caudad longitudinally 

 bisulcate. Lateral furrows distinct from the fifth plate caudad. Me- 

 dian keel low and flat, set off by furrows on the posterior plates, but 

 becoming first indistinct and finally disappearing cephalad. Last 

 dorsal plate with margin bowed out caudad as usual; the margin 

 mesally truncate. With a median longitudinal sulcus. 



Ventral plates long, longest cephalad, a little incurved near middle; 

 more strongly narrowed caudad, the tongue-like, distally rounded 

 caudal end lying well beneath the anterior portion of the succeeding 

 plate. Widely but distinctly depressed transversely across middle of 

 plate, but with no evident longitudinal furrows or sulci. Last ventral 

 plate narrowed caudad. Caudal margin mesally indented or emargi- 

 nate, the emargination very obtusely angular with the margin each 

 side convex and the corners rounded. A pair of bristles on caudal 

 portion. 



Process of coxopleura rather short, acutely one-pointed. No spines 

 proximad of tip of process or on caudal margin of coxopleura, but a 

 stout bristle at base of each process. Pores of small size, numerous; 

 the pore area not fully attaining the caudal margin, and removed from 

 lateral margin caudally by a wide space but only by a narrow space 

 anteriorlv. 



