586 PROCEEDINGS OF THE ACADEMY OF [AugUSt, 



rather indistinct, broad, darker median stripe containing a nar- 

 rower light one. Spinnerets brown. Epigijnum black. lAing 

 books yellow. Chelicera pale reddish-brown. Maxilke and labium 

 pale brown, the latter with darker base. Legs reddish -brown with 

 buff hairs and black sjiines, but no distinct aunulations. Palpi 

 colored like the legs. 



Comparisons. — Hentz's Micrommata carolinensis cannot be con- 

 sidered a synonym of undata, as Emerton and Marx have done, 

 since Hentz placed carolinensis in the tribe of the Biarcuatce, in 

 which the " upper and lower rows of eyes [are] bent and opposed," 



Genus DOLOMEDES Latr. 

 The following key will help to distinguish the species here 

 described, but the structure of the copulatory organs is the only 

 sure diagnostic character; there is one ? of what is probably 

 D. sexpimctatus Hentz in the Stone collection, but I have not 

 included it since it is not mature : 



A. — Posterior portion of the abdomen with transverse yellow 



markings of the shape of a W, urinator. 



B. — Posterior portion of the abdomen not so marked, . idoneus. 



32. Dolomedes urinator Hentz. (PI XXX, flg. 50.) 

 Dolomedes urinator Hentz, 1841. 

 1 Dolomedes tevebrosus Hentz, Emerton, 1885. 

 Dolomedes urinator Hentz, Marx, 1889. 

 Dolomedes tenebrosus Hentz, Stone, 1890. 

 ? Dolomedes iirinator Hentz, BanlvS, 1893. 



( 9 ? , but np dd, from Philadelphia, Chester county, Bucks 

 county, Lancaster county, York Furnace, Pa. ) 



Eyes. — First row broader than the second by less than the 

 diameter of one of its lateral eyes, lateral eyes slightly larger and 

 higher. Eyes of the second row slightly more than their diame- 

 ter apart. Third row broader than first, its eyes fully as large as 

 the eyes of the second row^ 



Fonn. — Cephalothorax flat and broad, rounded, its greatest 

 diameter equaling the length from the third eye row backwai'd, in 

 front more than one-half its greatest transverse diameter, highest 

 behind the middle. Chelicera less than twice the height of the 

 head in front. Legs slender. Sternum broader than long. 



Dimensions. — Length of cephalothorax, lO.o mm. 



length of abdomen, 14 mm. 



Length of first leg, 42 mm. 



