1902,] NATURAL SCIENCES OF PHILADELPHIA. 589 



black, labium and maxilkv black basally but yellowish distally. 

 Legs distinctly marked and annulated Avith deep reddish-brown and 

 yellowish on all Ihe joints except the metatarsi, which are black- 

 ish. The palpi are colored like the legs. 



Comparisons. — This form differs markedly in the epigynum 

 from the form here described as urinator, but is otherwise very 

 similar. 



I have been obliged to describe it as a new species, though the 

 same form may have been previously described, for the following 

 reasons: of the described American larger species of Dolomedes, 

 those of Walckeuaer and C. Koch are altogether insufficiently 

 characterized. Of Hentz's species, teiiax and hastulatus are ex- 

 cluded by the character of their eyes, and sexpundatus by its 

 smaller size and very different coloration, and scriptus, alhineus 

 and lanceolatus by their different coloration. There remains 

 D, tenehrosMS, Hentz's full description of which is as follows: 

 " Livid brown; abdomen and cephalothorax varied with blackish 

 angular markings; feet annulated with blackish; fi'equently meas- 

 uring over four inches from the extremity of the first pair of legs 

 to that of the fourth pair; male with legs 1, 2, 4, 3." This form 

 may be identical with my idoneus, but Hentz's description charac- 

 terizes no better than do any of Walckeuaer' s, and Hentz's figure 

 of the eyes (fig. 12, PI. XIX) does not agree with the eye 

 arrangement in idoneus ; and further, Hentz states that tenehrosus 

 " does not seek the vicinity of water, near which it was never 

 seen, but dwells generally in elevated dry places," while both 

 specimens of idoneus were found near watei*. Hentz's description 

 is not adequate in this genus where the structure of the copulatory 

 organs is a necessary diagnostic, and it is best to regard tenehromis 

 as insufficiently characterized, to drop the name, and thus avoid 

 future futile attempts to recognize it. 



D. idoneus is readily distinguished in its epigynum from the form 

 described by Emerton as "i). tenehrosus Hentz," yet Hentz's de- 

 scription ai)plies ecjually well to Emerton' s specimens as to those of 

 idoneus. 



Banks states of D. scriptus Hentz: " What has been taken as 

 D. tenehrosus Hentz is this species. What I feel sure is D. scriptus 

 H. has the epigynum as figured by Enuu-lon for D. tenehrosus and 

 very similar to that of D. scajmlaris as figured by Keyserling. 



