OXYSTOMATOUS AND ALLIED CRABS OF AMERICA jy 



outer angles. The quadrangular space between either one of these 

 teeth and the next tooth is about subequal or very slightly greater 

 than the length of tliis latter tooth; between tliis latter tooth and the 

 slender postocular spine that follows it a triangular sinus intervenes. 

 The postocular spine is strongly curved and inclinded inward . Postor- 

 bital spine similar. Ocular peduncles short and wide, similar to 

 those of R. nitidus. Wrist with a rudimentary spine; manus with 

 a slender spine above and three below; prehensile edge of immobile 

 finger armed with five small spines; dactyls of ambulatory legs 

 sickle-shaped. 



Measurements (after figure by Milne Edwards and Bouvier). — 

 Width of carapace just behind lateral spines 13/3, width of front lYz 

 mm. 



Range . — Unknown.* 



Genus RANILIA Milne Edwards 



Ranilia Milne Edwabds, Histoire naturelle des Crustaces, vol. 2, p. 195, 1837 



(type, R. muricaia Milne Edwards). 

 Notopus De Haan, Fauna Japonica, p. 138, 1841 (type. A'', rumphii Rathbun, 



1897= A'', dorsipes De Haan, 1841, not Cancer dorsipes Linnaeus, 1758). 

 Raninops A. Milne Edwards, Bull. Mus. Comp. Zool., vol. 8, p. 34, 1880 (type, 



R. conslrictus A. Milne Edwards, 1880). 



Carapace broad oval. Orbits directed very obliquely downward 

 from the rostrum, together forming an inverted V, and invisible from 

 above; eyes stout. Antennae directed forward, basal article a little 

 dilated inward. Third article of outer maxiUipeds longer than 

 second. The sternal plastron becomes linear between the first pair 

 of ambulatory legs, but between the second and third pairs it enlarges 

 again in a slightly concave, hexagonal disk. Last pair of legs not 

 remarkably reduced. 



East and west Atlantic and east and west Pacific Oceans. 



analogous species of ranilia on opposite sides of the continent 



Atlantic Pacific 



muricata. angustata. 



constricta. fornicata. 



KEY TO THE AMERICAN SPECIES OF THE GENUS RANILIA 



A^ Manus with a spine on upper margin. 



B^ Carapace about 1.4 times as long as wide. Dactyl of third 



ambulatory broad, its upper margin nearly straight _ muricata (p. 18) 



B2. Carapace narrower, smoother, and more glabrous angustata (p. 19) 



A^. Manus without spine on upper margin. 



B'. Dactyl of third ambulatory crescentic constricta (p. 20) 



B2. Dactyl of third ambulatory with convex lower border, upper 



nearly straight fornicata (p. 20) 



• It is not certain that this species belongs to the American fauna, but I follow A. Milne Edwards and 

 Bouvier in grouping it here. 



