•^24 Hentz^s Descriptions of the 



Observations. The habits of the animals of this subgenus 

 are but Httle known, owing to the obscure locations which 

 they select. They are probably nocturnal. 



ATYPUS NIGER. 



Description. Deep black ; cephalothorax flattened, horny, 

 with three depressions ; a white membrane at the base of the 

 cheliceres. A small species. 



Observations. A solitary individual (a male) was found in 

 June, on newly turned soil, at Northampton, Mass., by the 

 son of the late Prof W. D. Peck. I am not acquainted 

 with A. rujipes found by Mr. Milbert, near Philadelphia. 



Habitat. Massachusetts. 



PI. VIII. Fig. 1. Atypus nigpr. a. Its tropin, h. Its eyes. 



Genus. Dysdera. Latr. Walck. 



Characters. Cheliceres large, fangs articulated inward ; 

 'inaxillcB straight, wide at base, narrowed above the insertion 

 of the palpi, inner edge cut obliquely towards the point ; lip 

 half as long as the niaxillcB, emarginate at tip ; eyes six, 

 subequal, four in a line curved towards the base, and one each 

 side Clearer the anterior edge, but leaving an open space 

 between them ; feet, first pair longest, the second and fourth 

 nearly equal, the third shortest. 



Habits. Araneides sedentary, dwelling in silken tubes, 

 under stones or in crevices. 



Observations. The large size of the cheliceres, and other 

 minor characters, show some affinity to Mygale. The only 

 species here described being made known to me by Dr. T. W. 

 Harris, I am not acquainted with many facts necessary to give 

 a good history of this subgenus. 



DYSDERA INTERRITA. 



Description. Ferruginous ; cephalothorax and trophi 

 piceous. 



Observatio7is. This species was communicated to me by 

 my excellent friend Dr. T. W. Harris, of Massachusetts, who 



