260 Bulletin Vanderbilt Marine Museum, Vol. Vll 



The ambulatory legs of both sexes are similar, successively 

 decreasing in length from the third to fifth pairs, slender, moder- 

 ately compressed laterally, muricate, weakly so on the merus, 

 the size and number of spines increasing on the carpus, propodus 

 and dactyl; the inferior margin of the propodus is also armed 

 with a double longitudinal series of long, sharp spines and inter- 

 mediate tufts of bristles ; the dactyl is slender, very curved, slightly 

 more than one-half as long as the related propodus, with the dis- 

 tal third forming a very sharp curved tooth. 



One of the male specimens measures about 165 millimeters 

 total length, of which 95 millimeters represents the body length 

 and 70 millimeters, the extended portion of the great cheliped, 

 the total length of this great cheliped being 105 millimeters. A 

 female specimen has a total length of 120 millimeters, 98 milli- 

 meters of which represents the body length and 22 millimeters, 

 the extended portion of the great cheliped, the total length of 

 this great cheliped being 55 millimeters. 



The ova are very small, of about 0.4 millimeters long diame- 

 ter; the "sponge" or egg-mass carried by a single female con- 

 taining an estimated five thousand or more ova. 



References: Cancer cementariu^, Molina, J. I., Sulla Storia 

 naturale del Chili, 1782, p. 207 ; publ. anonymously, 1776. 



Palaemon caementarius, PoEPPiG, E., in Wiegmann's, A. F. A., 

 Archiv. f . Naturg. Berlin, 1836, Bd. II, pt. I, p. 143. 



Bithynis caementarius, Rathbun, M. J., Proc. U. S. Nat. Mus., 

 1910, vol. XXXVIII, p. 604. 



Palaemon gaudichaudii, MiLNE Edwards, H., Hist. Nat. Crust., 

 1837, t. II, p. 400.— Milne Edwards, H. et Lucas, H., in 

 d'Orbigny's, A., Voy. Amerique Meridionale, Paris, 1844, t. 

 VI, pt. I, p. 37, atlas, t. IX, pi. 17, fig. 2, color. 



Bithynis caementarius gaudichaudii, Rathbun, M. J., op. cit., 

 p. 560, pi. 54, fig. 1. 



