1904.] NATURAL SCIENCES OF PHILADELPHIA, 657 



behind widely truncate. Frontal plate clearly separated. Prebasal 

 plate well exposed. Basal plate twice wider than long, with no indi- 

 cation of a median furrow. 



Antennse short, attenuated distally, the ultimate joint little shorter 

 than the two preceding together; all articles sparsely hirsute with 

 short fine hairs. 



Claws of prehensorial feet when closed falling much short of the 

 front of the head; femora unarmed; tooth of claw large, acute; front 

 margin of presternum deeply excavated. 



All ventral scuta marked with a distinct median furrow, from the 

 posterior end of which extends outward over each half to the sides a 

 shallow^ oval impression in front of the posterior margin. 



Anterior spiracle moderate, a little elongate subvertically, the second 

 similarly shaped and but little smaller ; others circular, very gradually 

 decreasing in size caudally. 



Last ventral plate very wide; sides convexly rounded, strongly 

 converging caudally. 



Last pleurae much enlarged; pores serially arranged along and be- 

 neath the last ventral plate. 



Anterior pair of legs distinctly shorter and more slender, the legs 

 regularly increasing in size from the first to about the sixth pair. 



Anal pair of legs scarcely shorter than the penult, a little more slen- 

 der, armed with a claw. 



Pairs of legs 71-75. Length 60-82 mm,; width of largest specimen 

 2.2 mm. Length of antennae of largest specimen 4 mm. 



Locality. — Pacific Grove and Palo Alto, California, 



This large and handsome species cannot be the form described by 

 Wood under the name epileptica from an individual captured near 

 Puget's Sound, The latter species is apparently much more like im- 

 perialis BroL, the type of which comes from near the same locality. 

 According to the published descriptions and figures, these species agree 

 with each other and difTer from ruhelliana, among other points, in 

 having the prebasal plate covered and in the larger number of legs 

 (81-83 pairs). 



