THE GKAPSOID CEABS OF AMERICA. 91 



PINNOTHERES SILVESTRII Nobili. 



Pinnotcres silvcstrii Nobili, Boll. Mus. Zool. Anat. Comp. R. Univ. Torino, 

 vol. 16, No. 402, 1901, p. 11 (type-locality, San Vicente, Chile; holotype 

 in Mus. Zool. Turin) ; Revista Chilena Hist. Nat, vol. 6, 1902, p. 235 

 (repetition of original description). 



Pinnotheres silvestrii Rathbun, Proc. U. S. Nat. Mus., vol. 38, 1910, p. 587. 



Diagnosis. — Entire body and appendages thoroughly calcified and 

 hard. Carapace without furrows. Dactyli of legs very short. 



Description of female (after Nobili). — Carapace a little wider than 

 long, completely calcified and therefore very hard, flat except an- 

 teriorly and toward the lateral and posterior margins where it is bent 

 down ; bare and smooth with a luster like porcelain. Frontal margin, 

 pterygostomian region, infero-posterior parts and margin of abdo- 

 men covered with a grayish tomentum. No furrows on the carapace, 

 but two very slight and rather wide depressions near gastric region, 

 and two impressions at sides of cardiac region. Fronto-orbital bor- 

 der rather wide ; front vertically deflexed and produced at sides where 

 it meets orbit in a very distinct acute lobe; between this lobe and 

 the interantennular partition, the frontal border is deeply sinuous. 

 Orbits invisible from above, subcircular; ocular peduncles short, 

 stout, obconical. Antero-lateral margin rather long, separated from 

 the anterior margin by a fairly well-marked angle, and from the 

 postero-lateral margins by a more distinct angle; these last are 

 directed obliquely backward. 



Maxillipeds slightly oblique and rather pilose; merus subellipsoid, 

 broadly truncate at end; dactylus claw-shaped, exceeding in length 

 the preceding segment. 



Chelipeds rather large, subequal, calcified like the carapace; out- 

 side bare and smooth, inside thickly pilose; fingers somewhat curved, 

 excavated and incurved at tip, prehensile surface bearing long, stout 

 hairs. 



Legs short, stout, calcified, pilose along lower surface, along articu- 

 lations and on outer face of merus; dactyls very short. Abdomen 

 calcified. 



Measurements. — Female holotype, length of carapace 12, width of 

 same 14 mm. 



Range. — Known only from the single type female taken at San 

 Vicente, Chile. 



PINNOTHERES MARGARITA Smith. 



Pinnotlieres margarita Smith, in Verrill, Amer. Nat., vol. 3, 1869, p. 245, 



footnote (type-lorality, in the Pearl Oyster, Alargaritophora fimhriata, 

 of the Bay of Panama; holotype female in Peabody IMus. Yale Univ.) ; 

 Trans. Connecticut Acad. Arts and Sci., vol. 2, 1870, p. 166. 



Diagnosis. — Legs of second pair unequal in female, propodus and 

 dactylus of right leg much longer than those of left. Body and 



