THE SPIDER CRABS OF AMERICA 127 



BATRACHONOTUS NICHOLSI Rathbun 



Plate 39, figs. 5-8 



Batrachonotus nicholsi Rathbun, Proc. U. S. Nat. Mus., vol. 17, 1894, p. 55 

 (type-locality. Gulf of California, lat. 29° 30' N., long. 112° 40' W.; 

 holotype. Cat. No. 18107, U.S.N.M.); vol. 21, 1898, p. 570. 



Diagnosis. — Postorbital tooth reaching or nearly reaching end of 

 eye. No large tooth on immovable finger of male. Antenna! spines 

 divergent. 



Description. — Compared to B. fragosus, the granulation is every- 

 where coarser and more beadlike. Two enlarged tubercles or spines 

 on branchial margin. Rostral teeth more acute; basal antennal 

 spines more produced and very divergent from each other, the dis- 

 tance between the tip of each spine and the tip of the nearest rostral 

 tooth being more than twice as great as between the tips of the rostral 

 teeth. Supraorbital margin more elevated. Sternum behind the 

 chelipeds not completely granulate, the granules larger, the seg- 

 ments bearing the ambulatory legs having only one or two irregular 

 rows of granules, the depressions between the segments smooth. 



Chelipeds very rough, the immovable finger without an enlarged 

 tooth. First leg a little more than one and a half times as long as 

 carapace. 



Variations. — While in most of the specimens the dorsal protuber- 

 ances are crowned by a stout spine, varying in length, sometimes one 

 or more of these is replaced by a tubercle. In the type females, the 

 tubercles are very small, and the smooth space between regions is 

 greater than in any other specimens. 



Measurements. — Male (21782), length of carapace to tips of ros- 

 trum 9, width without spines 7.9 mm. Female (21869), length 7.5, 

 width 6.5 mm. 



Range. — ^Lower California, Mexico, from Abreojos Point on the 

 west coast to Gulf of California. Depth, 12 to 145 fathoms. 



Material examined. — See table, page 128. 



Genus PYROMAIA Stimpson 



Pyromaia Stimpson, Bull. Mus. Comp. Zool., vol. 2, 1871, p. 109; type, P. 



cuspidala Stimpson. — A. Milne Edwards, Crust. R6g. Mex., 1879, p. 197. 

 Apiomaia von Martens, Zool. Rec, 1871 (1873), p. 182; substituted for 



Pyromaia. — Miers, Journ. Linn. Soc. London, vol. 14, 1879, p. 651. 



Carapace pyriform, convex, rough with tubercles and spines; 

 rostrum simple, well developed; supraorbital spine usually present; 

 postorbital spine large, distant from the ocular cavity, and curved 

 around end of eye, tip directed forward. Basal article of outer 

 antennae long and narrow, tapering anteriorly; movable portion very 

 slender. Epistome a little wider than long. Buccal cavity not 



