OXTSTOMATOUS AND ALLIED CRABS OF AMERICA 123 



D2. Lateral and posterior margin of carapace not marked by 

 a continuous beaded line. 

 E*. Sixth segment of male abdomen with a marginal spine 



overlapping fifth segment Leucosilia (p. 170) 



E^. No spine on male abdomen. Exognath not dilated, 



outer margin nearly straight. Chelipeds stout.Randallia (p. 171) 

 A^. Merus of external maxillipeds less than half the length of the 

 ischium measured along the inner border. Fingers slender, 



of subequal width throughout LEUCOSIINAE " (p. 183) 



B'. Posterior half of carapace with seven spines. Anterior half of 



carapace with three spines on either side Callidactylus (p. 192) 



B2. Posterior half of carapace with not more than five spines, 

 usually three or four. Anterior half of carapace with no 

 spines or with one spine on either side. 



C Posterior half of carapace with three spines Iliacantha (p. 183) 



C'. Posterior half of carapace with four spines (exceptionally 



showing trace of a rudimentary fifth) Leucosia (p. 194 



Subfamily Ebaliinae Stimpson 



Ebaliinae Stimpson, Bull. Mus. Comp. Zool., vol. 2, p. 159, 1871. — Ihle, Die 

 Decapoda Brachyura der Sibog a-F,xpedition, Monogr. 39b*, p. 205, 1918. 



Surface of carapace uneven. Chelipeds of moderate length. Palm 

 and fingers normal, fingers not very thin or very elongate. The 

 dactylus moves often in an oblique plane. Anterior margin of 

 buccal cavity arcuate, the middle part in front of the line of the 

 anterior pterygostomian region. Epistome and infraorbital lobe 

 well developed. The pterygostomian margin extends either slightly 

 or distinctly forward and terminates in an indentation. Merus of 

 external maxillipeds half or more than half the length of the ischium 

 measured along the inner border. Very often the first abdominal 

 segment in the female is under the carapace, and the abdominal 

 formula is 2+3+4 to 6+7 or 2+3 to 6+ 7. 



Genus EBALIA Leach 



Ebalia Leach, Malacostraca Podophthalmata Britanniae, text of pi. 25, 1817 

 [type, E. tuberosa (Pennant, 1777) = S. pennantii Leach, Zoological mis- 

 cellany, vol. 3, p. 18, 1817]. — Alcock, Journ. Asiat. Soc. Bengal, vol. 65, 

 p. 185, 1896. 



Carapace rhomboid or pentagonal or hexagonal, commonly bud 

 not alwaj^s a little broader than long; its regions usually well definen 

 and tumid, tumid portions nodular or granular; its posterior margit 

 is generally a little prominent and either bilobed or with its extreme 



" In connection with the use of Leucosiinae for this group of genera, attention is called to a decision made 

 by me in "A Revision of the Nomenclature of the Brachyura" (Proc. Biol. Soc. of Washington, vol. 11, 

 p. 160, 1897). In 1810, Latreille in his "Considerations GCnerales sur TOrdre Naturel des Animaux Com- 

 posant les Classes des Crustacfc, des Arachnides, et des Insectes," p. 422, specified the type of Leucosia as 

 L. nuciea Fabricius (Supplementum entomologiae systematicae, p. 313, 179S) = Cancer nucleus Linnaeus, 

 1758. In 1817, Leach (Zoological miscellany, vol. 3, p. 19) made this species the type of a new genus. Ilia. 

 Leucosia Fabricius as typified by Latreille, therefore, takes precedence of Ilia, a synonym, and also prece- 

 dence of Leucosia Leach (op. cit., p. 21) for the species L. craniolaris Fabricius, 1798— Canc<r cTaniolarij 

 Linnaeus, 17.58. For this latter genus I proposed, in 1897, loe. eit., the name Leucosides. 



80232—37 9 



