480 
Wisconsin Academy of Sciences, Arts and Letters. 
MARPISSA C. K. 1846. 
Type, mucosa Clerck. 
1845. Attus H. (rupicola, familiaris), Jour. Bost. Soc. Nat. Hist. Y. 
1846. Marpissa C. K. (in part), Arachn., XIII, p. 56. 
1875. Attus H. (rupicola, familiaris), Occ. Pap. Bost. Soc. Nat. Hist. 
II, p. 56. 
1888. Marptusa P., Wis. Acad. Sciences, Arts and Letters, VII, N. A. 
Att., p. 80. 
1891. Marptusa Em., Trans. Conn. Acad., VIII, p. 19. 
1892. Marptusa B., Proc. Acad. Nat. Sci., Phila., p. 79. 
1894. Marptusa P., Occ. Pap. Nat. Hist. Soc. Wis., II, 2, p. 86. 
1901. Marpissa P. O. P. C., Biol. Cent. Am., Arachn., Aran., II, p. 248. 
1901. Marpissa E. S. Hist. Nat. Araign. 2me Ed., II, p. 610. 
1905. Marpissa B. Am. Nat., XXXIX, p. 321. 
Although four species of Marpissa have been described from 
the United States, we are unable to distinguish more than three. 
Minor and melanura of Cambridge, from Mexico, are forms of 
californica. There is more difference between rupicola H., 
which Mr. Banks considers a good species, and undata, but after 
studying Mr. Banks’ specimens of rupicola (a male and a 
young female), and a mature female in our collection, we con¬ 
sider it a variety of undata with considerably more tawny color 
on both abdomen and cephalothorax, and with the first legs rela¬ 
tively longer, in the male. 
The variation in the form of the epigynum, as shown by Cam¬ 
bridge, seems to be due to the depth of color in the skin. We 
find the same variation in californica. 
The spiders in this genus are large and flat, with a wide ab¬ 
domen which is marked by an angular central band. 
Cephalothorax long, wide, flat and low. widest behind the 
dorsal eyes. Eye-region occupying but little more than 1-3 of 
the cephalothorax, about 1-4 wider than long, and equally wide 
in front and behind. Eront eyes in a straight or slightly curved 
row, the middle about twice as large as the lateral. Second 
row halfway between the others or a little nearer the first. 
Third row plainly narrower than the cephalothorax. Lower 
margin of falx with a single tooth. Sternum narrowed in front. 
