19 



[From the Bost. Journal Nat. Hist., iv, 223. Art. xvi.] 



Genus. Atypus, Latr. Oletera^ Walck. 



Characters. CheUceres large with a fang nearly equal to 

 their length, articulated downward ; maxillm tapering upward, 

 insertion of the palpi lateral ; Up concealed ; eyes eight, ^ubequal, 

 collected in front of the cephalothorax, two in the centre, and on 

 each side of these there is a cluster ; feet 4. 1. 2. 3. 



Habits. Araneides sedentary, dwelling in silk tubes placed 

 in the ground. [224] 



Observations. The habits of the animals of this subgenus 

 are but little known, owing to the obscure locations which they 

 select. They are probably nocturnal. 



Atypus niger. 

 PI. 2, fig. 1. a and 5. 



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, rufipes found by Mr. Milbert, near Philadelphia. 



Habitat. Massachusetts. 



[Marietta. 0., d Wm. Holden. j. H. E.] 



Genus. Dysdera. Latr. Walck. 



Characters. Cheliceres large, fangs articulated inward; 

 maxillcB straight, wide at base, narrowed above the insertion of 

 the palpi, inner edge cut obliquely towards the point ; lip half as 

 long as the maxillce, emarginate at tip ; eyes six, subequal, four 

 in a line curved towards the base, and one each side nearer the 

 anterior edge, but leaving an open space betiveen them ; feet, first 

 pair longest, the second and fourth nearly equal, the third 

 shortest. 



