Boone, Crustacea, Cruise of ''Alva," 1931 77 



setae ; the propodus with two longitudinal grooves on each lateral sur- 

 face ; the dactyl, which is very slender and acuminate, is almost as long 

 as the merus, is fluted, having three carinae separated by two grooves 

 on each lateral surface, and with both margins setose. The fifth pair 

 of legs are fairly stocky ; the merus with a strong, subdistal spine on 

 its outer lateral margin ; the propodus and dactyl are only moderately 

 expanded, suboval, with setigerous margins. 



Remarks: It is of interest to note that of the fifteen specimens 

 before me, ranging in size from less than one inch carapace width to 

 two and a quarter inches, only three specimens have the fourth antero- 

 lateral spine equally developed on opposite sides of the carapace. In 

 two specimens this fourth spine is about as large on one side as the 

 adjacent third spine, while on the opposite side, the fourth spine is a 

 mere spinule. In four specimens, including one of the largest in the 

 series, the fourth spine is so rudimentary on both sides that it appears 

 obsolete, being concealed in the setae. In only four specimens is the 

 fourth spine developed about equally on both sides of the carapace 

 and visible as a distinct small spine. In the other five specimens the 

 fourth spine is variously medium size on one side of the carapace to 

 practically obsolete on the related opposite side. 



Likewise there is much variation in the granulation of the ridge of 

 the antennal process of the first peduncular segment. In some crabs 

 this ridge is nothing more than a heavy blunt ridge; on the majority 

 the ridge is beaded irregularly by coarse granules, while on a few the 

 granules are produced into conical spinules. 



References : Cancer prymna Herbst, Naturg. Krabben und Krebse, 

 Bd. Ill, p. 41, atlas pi. 57, fig. 2, 1798. 



Thalamita prymna H. Milne Edwards, Hist. Nat. Crust., t. I, p. 461, 

 1934.— Krauss, Sudafrik. Crust, p. 25, 1843.— De Haan, Faun. 

 Japon. Crust, p. 43, pi. 12, fig. 2, 1837, — A, Milne Edwards, 

 Archiv. Nouv. Mus. Hist. Nat., Paris, ser. 1, vol. X, p. 360, 367, 

 1861; ihid., t. IX, p. 163, 1873.— Hess, Archiv. fur. Naturges., 

 Bd. 31, Abth. 1, pp. 140, 171, 1865.— Hoffman, in Pollen and Van 

 Dam, Recherches Faune Madagascar, Crust., vol. V, p. 9, 1874. — 

 KossMAN, Crust. Roth Meer, 1877, p. 47, (partim.). — Streets, 

 Bull. U. S. Nat. Mus., vol. 7, p. 108, 1877.— (Misspelled: 

 pyrmna). — Neumann, Cat. Pod. Crust. Heidlb. Mus., p. 24, 

 1878.— de Man, Notes of the Leyden Mus., vol. II, p. 180, 1880. 

 — Archiv. fur Naturges., vol. LIII, Abth. I, p. 333, 1887. — Journ. 

 Linn. Soc. Zool., vol. 22, p. 75, pi. 4, figs. 5, 6, 1887-88.— In 



