466 BULLETTISr 129, UNITED STATES NATIONAL. MUSEUM 



dicantha or diacantJia, to this same form, while the trispinosa figured 

 by him is of the series 2, described above, which I now call trispinosum, 

 variety. The form above called series 3 was not named until 1867 

 when Desbonne's description and figure were published under the 

 name, Pericera nodipes. It must now be known as Macrocoelomxi 

 trispinosum nodipes. 



MACROCOELOMA TRISPINOSUM (LatreUle) 



GRASS CRAB (Browne). SPONGE CRAB (Jarvis). DECORATOR CRAB 



(Wilson) 



Plate 166, fig. 1; plate 167 



Cancer 9, Browne, Nat. Hist. Jamaica, 1756, p. 422, pi. 48 (not 46), fig. 2. 



Pisa trispinosa Latreille, Encyc. M4th., Hist. Nat., vol. 10, 1825, p. 142 

 (type-locality, Nouvelle Hollande? [an error]). 



Pericera trispinosa Guerin, Icon. Regne Anim., Crust., pi. 8, figs. 3, 3a. — 

 Milne Edwards, Hist. Nat. Crust., vol. 1, 1834, p. 336 (Antilles). — 

 AuRiviLLius, K. Sv. Vet.-Akad. Hand., vol. 23, pt. 1, 1889, p. 55, pi. 2. 

 fig. 2. Not Gundlach and Torralbas, An. Acad. Habana, vol. 36, 1899 

 (1900), p. 365, text-fig.; reprint, 1917, p. 21, pi. 5, fig. 12. 



Pericera dicantha A. Milne Edwards, Crust. Reg. Mex., 1875, p. 57 (type- 

 locality, Mujeres [not Majores], 12 fathoms; type. Cat. No. 1919, M.C. Z.). 



Pericera diacantha A. Milne Edwards, Crust. Reg. Mex., 1875, pi. 15, figs, 

 3-3 c. 



Macrocoeloma trispinosa Miers, Journ. Linn. Soc. London, vol. 14, 1879, p. 

 665. 



Macrocoeloma diacantha Miers, Challenger Rept., ZooL, vol. 17, 1886, p. 79. 



Macrocoeloma trispinosum Rathbun, Proc. U. S. Nat. Mus., vol. 21, 1898, 

 p. 576. 



Macrocoeloma diacanthum Rathbun, Proc. U. S. Nat. Mus., vol. 21, 1898, p. 

 576; Bull. U. S. Fish Comm. for 1900, vol. 20, pt. 2 (1901), p. 74 (part). 



Diagnosis. — -Rostral horns adjacent and subparallel at base. 

 Postero-lateral projections sharp spines. Four dorsal bosses each 

 with a sharp tubercle at tip. 



Description. — Body and appendages covered with very shorty 

 brown hairs which form a sort of velvet. Carapace thick and very 

 swollen, wide at line of orbits, narrowing distinctly in hepatic portion^ 

 widening again posteriorly. Four large rounded prominences, the 

 anterior or gastric one the highest, forming together a cross in the 

 center of the carapace and each bearing a more or less sharp tubercle 

 at the summit. Front formed of two flattened, sharp horns, which 

 are adjacent and subparallel at base, and distally divergent. Upper 

 margin of orbit deeply emarginate, the ocular and postocular teeth 

 prominent, the former curved forward. Near the inner angle of the 

 basal article of the antenna there is a rather long, oblique spine 

 entirely visible from above; flagellum slender, on either side of the 

 rostrum but not reaching the end of the horns. At the postero-lateral 

 angles of the carapace there is a stout, regularly tapering, sharp spine 



