180 GEOLOGY AND PALEONTOLOGY OF THE WEST INDIES. 



Orbits long, shallow trenches, extending the whole width of the carapace 

 except for the front, and bordered above except for the outer third by a narrow 

 surface of varying depth, similar to that in Uca ( = Gelasimus). 



Sandomingia seems to be nearest Uca Leach, 1 the genus of fiddler 

 crabs. Uca has the same shape of carapace, with similar depressions, 

 orbits occupying nearly the whole width of carapace, with a thickened, 

 bimarginate upper edge. On the other hand, in Sandomingia the 

 antero-lateral angle is bidentate, there is a definite notch in the upper 

 margin of the orbit, the orbit is very shallow, and the chelipeds are 

 large and equal. 



The equality in the chelipeds suggests the possibility of this crab 

 being a portunid allied to the long-eyed forms, Podophthalmus and 

 Euphylax, but the latter have the orbits deeply hollowed at the outer 

 ends to hold the cornese and lack the facet-like upper margin of the 

 orbit. 



Sandomingia yaquiensis, new species. 



(Plate 8, Figures 1 and 2.) 



Type locality. Lower half of the valley of the Yaqui del Norte 

 River, in the northern part of Santo Domingo, Haiti; probably lower 

 Miocene; W. M. Gabb, collector; 1 specimen. 



HolotypeCat. No. 2257, Mus. Phila. Acad. Nat. Sci. 



Measurements. Length of carapace, exclusive of rostral lobe, 23 

 mm., width of carapace at antero-lateral angles (approximate, because 

 tips of teeth are broken off) 42 mm., width of frontal lobe at base 3 mm. 



The following is a description of this species : 



Carapace flat in the middle, sloping rapidly down to the anterior and lateral 

 margins; surface smooth and a little uneven; a shallow furrow defines the 

 gastric region. Anterior margin finely granulate, granules not in a single 

 row; lower edge of flat supraorbital space or "eyebrow" having a single row 

 of granules; "eyebrow" very narrow, height about one-fifteenth of its length 

 in a transverse direction, inner end at base of frontal lobe. Surface of orbit 

 smooth and shallow. Antero-lateral tooth an equilateral triangle; it and the 

 tooth behind it are separated by a U-shaped interspace and project about 

 equally sideways; the tips are broken off, so that it is impossible to tell exactly 

 about this. 



Chelipeds equal; only a portion of the merus or arm-joint of each is visible; 

 it is stout, triangular in cross-section, upper surface concave and smooth, 

 posterior and inferior margins blunt and granulate, anterior margin subacute 

 and furnished with tubercles of varying size arranged in two irregular rows. 



Superfamily OXYRHYNCHA. 



Family PARTHENOPID^. 



Genus PARTHENOPE Weber, 1795. 



Parthenope (Platylambrus) obscura, new species. 



(Plate 7, Figures 5 and 6.) 



Type locality. The Yaqui Valley at Cercado de Mao (Bluff 3); 

 Santo Domingo; lower Miocene; C. J. Maury, collector; 1916. 



1 Edinb. Encyc., vol. 7, p. 430, 1814. 



