— 130— 



About half or less than half as long as ceph'x., broad and deep, armed with a 

 comparatively strong fang; the inner edge only of furrow for reception of fang armed 

 wi h teeth ; upper and inner edges of anterior half armed with short spines, which also 

 extend part way around base of fang. 



Legs 4, I, 3, 2. 4, I, 2, 3, or 4, i, 2, 3; palpi lou'^. 3 tarsal claws. Claw of 

 jjalpus unarmed. Abdomen short oval. Spinnerets 4 pair, the upper pair long and 



slender. 



1. Nidivalvata marxii, n. sp.' Q i specimen. 

 (PI. V, figs. 8, 9, 10, 13, 23.) 



Ceph'x broadly oval 6 mm. long by 5 mm. broad. Caput back oi ocular prom- 

 inence not perceptibly elevated, slope down to dejjres^ion in center of ceph'x gradu- 

 al. Caput in front not much contracted on sides. 



Radial depressions all quite deep; the posterior one of the laterals on each side 

 seeming to unite with the central depression. The depressions, though distinct in this 

 specimen, have deepened somewhat by alternately being in alcohol and in the air 

 while being studied. 



In each anterior radial depression on sides of base of caput is a well marked de 

 pression, though not deep. 



Post-central eyes fully as large as the ant-centrals, eyes of the outer group almost 

 or quite touching. Ant-laterals dark orange, remainder transparent, legs. 4, i, 3, 2. 

 3rd 12 mm., 2nd Ili mm. Sternum longer than broad, with three distinct circular 

 punctures on each side. Abdomen broadly oval and bluntly rounded at each end; on 

 ventral surface narrowed in front. 



Armature. Very few hairs; short and fine on abdomen, longer and darker on 

 the 4 distal joints of legs. Metatarsus IV, with a row of spines on each side, and one 

 on under side, with additional spines at each end; tibial V, v/ith few long spines irreg- 

 ularly placed on upper side, 3 distinct rows, two on under side and one on anterior 

 side, with extra spines at each end. Patella two double rows of spines on upper surface. 

 Metatarsus III, 4 rows of spines, two upper and two lower edge: spines irregu- 

 larly placed on upper side. Patella III, patch of spines on upper anterior surface, 

 broadest at distal end; this is separated from a few spines on the posterior surface by 

 an oblique rounded line. Metatarsus II, two double rows of spines, one on anterior 

 surface, and one of long spines on under surface; tibia II and I, double row of long 

 spines on under surface, and single row of short spines on anterior surface. Metatar- 

 sus I, three rows of long spines on under and anterior surface. Palpus, tarsus and 

 tibia a somewhat double row of long spines on each side; patella, one or two spines 

 on anterior surface. 



Labium separated from sternum by a deep furrow. 



Colors. Upper surface Ceph'x and legs, olive brown. • Under surface legs dull 

 yellowish. Sternum a little darker. Maxillre dull rufous, with reddish hairs. Oc- 

 ular prominence black. Abdomen dull yellowish underneath, brownish yellow above, 

 with two rectangular rich dark brown spots on anterior end. Mandibles rufous. Col- 

 ors little changed in alcohol, not so bright however, and marks on abdomen disap- 

 peared. 



2. Nidivalvata angustata n. sp. 9 2, specimens. 



Ceph'x oblong, 5| mm. long by 4 mm. broad. Caput in front below eyes per- 

 ceptively narrowed; caudad of ocular prominence perceptibly elevated, making the 

 descent to the thorax steeper than in X. marxii. Legs 4, i, 2, 3. Anterior central 

 and lateral eyes dark, the others light; posterior centrals much smaller comparatively 



1 In honor of Dr, Geo. Marx. 



