OXYSTOMATOUS AND ALLIED CRABS OF AMERICA ^09 



Genus CLYTHROCERUS A. Milne Edwards and Bouvier 



Clythrocerus A. Milne Edwards and Bottvier, Bull. Mus. Hist. Nat., Paris, 

 vol. 5, p. 3S7, 1S99 [type, C. nitidus (A. Milne Edwards)]; Mem. Mus. Comp. 

 Zool., vol. 27, p. 99, 1902.— Rathbun, Bull. U. S. Fish Comm. for 1900, 

 vol. 20, pt. 2, p. 90, 1901. 



Resembles Q/clodorippe in the rounded carapace, the mediocre 

 sternal plastron, and the complete atrophy of the exopod of the an- 

 terior and intermediate maxillipeds. Differs in its small antennules, 

 completely retractile in the orbito-antennal cavity, in the valviform 

 peduncle of the very short antennae and the comparative shortness of 

 the ambulatory legs. 



East and west coasts of Middle America; Japan. 



KEY TO THE SPECIES OF THE GENUS CLYTHROCERUS 



A'. Only one lateral tooth or spine behind the orbital tooth. 

 B'. Front with two teeth, 



CK Carapace thick, smooth, and shining nitidus (p. 109) 



C2. Carapace flat, finely granulate. 



D'. Carapace with an indentation either side of lateral tooth. 



perpusillus (p. Ill) 

 D2. Carapace without marginal indentations. Carpus of 



male cheliped with a large inner plate laminatus (p. 115) 



B2. Front with three teeth. Carapace and appendages densely 



granulate. Margins of carapace spinulous granulatus (p. 119) 



A2. Two lateral teeth or spines behind the orbital tooth. 



B^ Distance between lateral spines greater than between fore- 

 most tooth and orbital tooth. Frontal teeth with short 



tips planus (p. 114) 



B2. Distance between lateral spines less than between foremost 

 tooth and orbital tooth. 



Ci. No spine above lateral spines. Two frontal teeth decorus (p. 118) 



C^. A spine above and between lateral spines. Three frontal 



teeth stimpsoni (p. 121) 



CLYTHROCERUS NITIDUS (A. Milne Edwards) 



Figures 26, 27; Plate 33, Figures 1, 2 



Cijclodorippe nitida A. Milne Edwards, Bull. Mus. Comp. Zool., vol. 8, p. 24, 

 1880 (type localities, Florida Keys and Grenada; cotypes in M. C. Z.). — 

 S. I. Smith, Bull. Mus. Comp. Zool., vol. 10, p. 7, pi. 2, figs. 1, lb, 1882.— 

 BouviER, Bull. Soc. Philom. Paris, ser. 8, vol. 9, p. 66 [13], 1898.- Rathbun, 

 Bull. Lab. Nat. Hist. State Univ. Iowa, vol. 4, p. 293, 1898. 



Clythrocerus nitidus A. Milne Edwards and Bouvier, Mem. Mus. Comp. Zool., 

 vol. 27, p. 90, pi. 18, 1902. 



Diagnosis. — Carapace and appendages smooth and shining. Only 

 one lateral tooth or spine. 



Description. — Carapace entirely smooth, thick, not swollen, slightly 

 depressed transversely behind the front. Branchio-cardiac and uro- 

 gastric sutures distinct. Front deeply depressed and with a broad 

 V-shaped median sinus; its lateral angles are at the same level as the 



