84 Bulletin, Vanderhilt Marine Museum, Vol. II 



Synonymy. — Pisa antilocapra Stimpson, Bull. Mus. Comp. Zool., vol. 

 2, p. 110, 1871. — A. Milne Edwards and Bouvier, Mem. Mus. 

 Comp. Zool., vol. 47, p. 383, pi. 11, figs. 4 and 5, pi. 12, fig. 3, text 

 fig. 19, 1923. 



Pisa praelonga Stimpson, Bull. Mus. Comp. Zool., vol. 2, p. Ill, 1871. 

 — ^A. Milne Edwards and Bouvier, Mem. Mus. Com. Zool,, vol. 

 47, p. 384, pi. 11, figs. 6 and 7, pi. 12, fig. 4, 1923. 



Nihilia erinacea A. Milne Edwards, Crust. Beg. Mexico, p. 133, pi. 

 25, 1878. 



Nibila antilocapra Rathbun, Bull. 129, U. S. Nat. Mus., p. 290, pis. 

 102, 103 and 239, 1925. 



Genus: LIBINIA Leach. 

 Libinia dubia H. Milne Edwards. 



Plate 24, fig. B. 



Name : This is one of the two species known as the common spider 

 crab of the East Coast of the United States. 



Diagnostic characters : Carapace with six median tubercles ; dor- 

 sal tubercles scarce. One spine situated at the angle of buccal cavity. 

 Carapace more pyriform than Libinia emarginata. 



Type: H. Milne Edwards gives the type localities as "cotes des 

 Etats-Unis, " and states that the type is deposited in the Paris 

 Museum. 



Recorded Distribution: Inhabits muddy shores, shallow water to 

 25 fms. It is very abundant from Cape Cod, Mass., to Texas, and has 

 also been reported occasionally in the upper West Indies. It is re- 

 corded from West Africa. 



Material examined: Two males. Long Island Sound, Northport, 

 Long Island, N. Y., July 7, 1922; one large male from the same lo- 

 cality, July 7, 1928. 



Color: Yellowish to light brick red in young specimens. Fre- 

 quently covered with mud, algae, anemones, etc. 



Technical description : Carapace pyriform and with the rostrum 

 slightly longer and more definitely bifid than in the associated species, 

 L. emarginata, which is more nearly hemispherical. Upper surface of 

 carapace very convex, regions sharply delineated; in the median line 



