382 BULLETIN 129, UNITED STATES NATIONAL MUSEUM 



A^. Carapace with smooth, obUque, branchial sulci. Rostral horns very short. 

 Minor teeth of orbit tuberculiform, inconspicuous. 



Subgenus Mithraculus, p. 421. 

 B'. Carapace broader than long. 



C. Antero-lateral margins cut into rounded loljes only. 

 D'. Antero-lateral margin cut into three lobes. 



E'. Posterior part of carapace eroded. Inner or anterior margin of 



cheliped laminate, up to middle of palm nodosus, p. 429. 



E^. Posterior part of carapace nodose, not eroded. Inner margin of 



cheUped not laminate coryphe, p. 426. 



D^. Antero-lateral margin cut into four lobes. Wrist smooth, margin not 



laminate nor dentate sculptus, p. 422. 



C^. Antero-lateral margins cut into spines or angular lobes or spines and 

 "lobes. 

 D^ Four antero-lateral protuberances behind the orbit. Wrist smooth 



above and with one inner tooth forceps, p. 431. 



D^. Three antero-lateral protuberances behind the orbit. Wrist more or 

 less uneven above. 

 E'. Carapace nearly half wider than long. Two lobes of basal segment 



of antenna equally advanced denticulatus, p. 428. 



E^. Carapace not much wider than long. Two lobes of basal segment 

 of antenna not equally advanced. 

 F^. Wrist obscurely tuberculate. Palm without tubercle on outer 



surface at articulation with wrist ruber, p. 432. 



F2. Wrist prominently tuberculate. Palm with small depressed 

 tubercle on outer surface at articulation with wrist. 



areolatus, p. 433. 

 B2. Carapace longer than broad cinctimanus, p. 438. 



DOUBTFUL SPECIES 



A'. Carapace one-fourth longer than wide, without spines or lateral angle. 



leucomelas, p. 421. 



A^. Not described Mithrax, sp. indct. (Valparaiso), p. 421. 



A^ Figured but not described. May be a young Mithrax "Manilatus poeyi 



Forns." *' 



ANALOGOUS SPECIES ON OPPOSITE SIDES OF THE CONTINENT 



Atlantic 



spinosissimus. 



acuticornis. 



hemphilli. 



verrucosus. 



coryphe. 



ruber. 



Pacific 



rostratus. 



spinipes. 



orcutti. 



helm. 



denticulatus. 



areolatus. 



SPECIES ONCE REFERRED TO MITHRAX, NOW IN OTHER GENERA *' 



Mithrax affinis Brito CenpeWo = ScM2ophrys aspera (Milne Edwards). 

 Mithrax asper Milne Edwards = Schizophrys aspera (Milne Edwards) . 

 Mithrax quadridentatus M.SicLesiy = Schizophrys aspera (Milne 

 Edwards) . 



" Gundlach and Torralbas, An. Acad. Habana, vol. 36, 1899 (1900), text-flg. on p. 330; reprint, 1917, 

 pi. [4], fig. 8. 

 *> See also the index to this volume. 



