OXYSTOMATOUS AND ALLIED CRABS OF AMERICA 59 



Description. — Carapace thick, much swollen transversely, and bent 

 down anteriorly; clothed with a scattered down which does not con- 

 ceal the test; surface smooth, punctate behind. Posterior branchial 

 regions dilated, their anterior limit a deep branchial furrow which 

 is interrupted a little before reaching middle of cardiac area; this 

 last is strongly marked except behind where its periphery is marked 

 by wide, shallow depressions. The cervical suture is represented in 

 its median part by a shallow median arc, concave forward, which 

 does not join the lateral parts. Front armed with two strong, 

 triangular, flat rostral horns, which reach to the level of the extremity 

 of the second article of the antennae and are deeply separated by a 

 furrow continued on the gastric region. A large postorbital spine 

 is conical and directed outward and a little forward. Lateral borders 

 unarmed and almost parallel. Latero-inferior regions unarmed. 



Ocular peduncles nearly as long as rostral horns and almost cylindri- 

 cal; armed in front with a small spine and terminating in a cornea very 

 Uttle dilated and with a deep sinus behind. The antennular peduncles 

 reach almost to the end of the antennal peduncles. Chelipeds of 

 male feeble, equal, covered with smooth scattered hairs; a spine on 

 upper distal border of merus and another outside overlapping carpus; 

 prehensile margins of digits dentate, the immobile finger ending in a 

 sort of fork which fits the tip of the mobile finger. The first two 

 ambulatories are smooth, cyhndrical; dactylus very long and strongly 

 curved; merus armed wdth a small spiae above at distal end. The 

 chela of the last two pairs of feet is formed by a very curved dactyl 

 opposed to a short projection of the propodus, armed with several 

 spines. 



Measurements. — Male holotype, total length of carapace 18, width 

 at base of anterolateral spines 9, maximum width of posterior branchial 

 regions 12.5 mm. 



Range. — Leeward Islands, Caribbean Sea. 



Material examined. — Off Nevis; 356 fathoms; station 151, Blake; 

 1878-79; 1 male holotype (M. C. Z. no. 6512). 



Genus DICRANODROMIA A. Milne Edwards 



Dicranodromia A. Milne Edwards, Bull. Mas. Comp. Zool., vol. 8, p. 31, 1880 

 (type, D. ovata A. Milne Edwards). — Filhol, La vie au fond des mers, 

 p. 127, 1885.— Ortmann, Zool. Jahrb., vol. 6, p. 549, 1892.— Bouvier, Bull. 

 Soc. Philom. Paris, ser. 8, vol. 8, p. 48, etc., 1896. — A. Milne Edwards 

 and Bouvier, Mem. Mus. Comp. Zool., vol. 27, p. 14, 1902. 



Arachnodromia Alcock, Deep-sea Brachyura, Investigator, p. 17, 1899 (type, A. 

 baffini Alcock and Anderson). 



Carapace narrow, ovoid, elongate, scantily hairy. The antennules 

 fold longitudinally under the broad rostral teeth and the eyes are 

 concealed in the deep orbital cavity. A strong crest on either side 

 of endostome; epistome triangular, the point joining the front. The 



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