172 Bulletin, Vanderbilt Marine Museum, Vol. Ill 



is a little shorter in heterochaelis in relation to the scaphocerite than 

 is the ease in armillatus. 



The large cheliped of heterochaelis is shorter than that of C. armil- 

 latus; the upper and lower transverse grooves are somewhat similar 

 but the supermarginal groove of the inner face of heterochaelis is con- 

 spicuous. The grooves and furrows of the dactyl are distinctly differ- 

 ent, and the shape of the great basal tooth of the hinged finger and 

 correspondingly the shape of the excavation on the lower finger are 

 also distinctive. 



The smaller chela in the male is broad, elongated. The palm is of 

 about equal length to the curved dactyl. The proximal dorsal area of 

 the palm is circumscribed by an impressed line ; the upper, distal mar- 

 gin is notched and a groove runs back from the notch on either side ; 

 the groove of the inner side is deeper and joins the posterior impressed 

 line ; the distal articular margin is tridentate ; the upper, median tooth 

 is small, obtuse, the lateral ones are more acute ; these teeth are fre- 

 quently brownish-black like the tips of the fingers. The upper finger 

 is broad, arched, beak-like; the lower finger has the tip bent upward 

 slightly, the cutting edge excavate, while that of the hinged finger is 

 produced to a median carina. 



The third and fourth pairs of ambulatory legs are moderately com- 

 pressed, the ischial spine inconspicuous or more often lacking ; the pro- 

 podus armed with eight or nine small, articulated spines; the dactyl 

 is flattish, curved, acute. The fifth legs are smaller, nearly terate ; the 

 dactyl similar to those of the preceding pairs. 



Synonymy. — Alpheus heterochaelis Say, Journ. Acad. Nat. Sci. Phila. 

 vol. 1, p. 243, 1818.— H. Milne Edwards, Hist. Nat. Crust., vol 

 II, p. 356, 1837. — GiBBES, Proc. Amer. Assoc. Adv. Sci., vol. 3, p 

 196, 1850. — KiNGSLEY, Bull. U. S. Geol. and Geograph. Surv., vol 

 4, p. 194, 1-878 ; Bull. Essex Inst., vol. X, p. 58, 1878 ; Proc. Acad 

 Nat. Sci. Phila. for 1880, p. 417, part ; Bull. Essex. Inst., vol. 14 

 p. 120, 1883. — Brooks and Herrick, Johns Univ. Circ, vol. 11 

 pp. 69-70, 1892 (life history) ; Mem. Nat. Acad. Sci., vol. V, pp 

 361-463, pi. 2, colored; pis. 16-20, 1892 (Embryology and life 

 history). — Rathbun, Proc. Wash. Acad. Sci., vol. 2, p. 152, 1900 

 Bull. U. S. Fish. Comm., vol. 20, pt. 2, p. 197, 1901, part.— 

 Coutiere, Proc. U. S. Nat. Mus., vol. 37, p. 485, 1910. 

 Crangon heterochaelis Hay and Shore, Bull. U. S. Bur. Fish., vol. 35, 

 p. 386, pi. 26, fig. 6, 1918.— ScHMiTT, Bidj. tot der Dierk., Am- 

 sterdam, Afl. 23E, p. 65, 1924. 



