THE CANCROID CEABS OF AMERICA 501 



PILUMNUS DIOMEDEAE Rathbun 



Plate 202, Figures 2 and 3 



Mliunnus diomedeae Rathbun, Proc. U. S. Nat. Mus., vol. 17, p. 3, advance 

 sheet, March 20, 1894; p. 85, July, 1894 (type-locality, off Havana, 184 

 fathoms; type, Cat. No. 9526, U.S.N. M.). 



Diagnosis. — Four long spines on each lobe of front. Carapace very 

 rough. Hah's extremely long. Spines of carpus and propodus of 

 ambulatory legs normal to the article. 



Description. — Carapace of moderate w^idth. Surface very rough 

 with acute granules or hair sockets; some and perhaps all of the hairs 

 long, yellow. Front with two produced oblique lobes each bearing 

 four slender spines; a longer incurved spine near antenna. Orbital 

 spines 9: 2 on the upper margin, one at the outer angle and 6 below; 

 of the 2 upper, one is next the antennal spine, the other at middle of 

 orbit; of the suborbital spines the two outermost are separated by a 

 deep narrow sinus, the two innermost are more advanced. There are 

 four strong antero-lateral spines including the orbital; between the 

 first and second there is a small supernumerary spine; the second 

 spine has an accessory spinule. Subhepatic and pterygostomian 

 regions spinulous; two small spines form a longitudinal line on the 

 process which bears the two spines at inner angle of orbit. 



Chelipeds unequal, spinous, long-hairy like the carapace. Merus 

 with surface minutely spinulous, margins spinous, upper margin with 

 two huge spines at distal end. Carpus w^ith outer surface spinous and 

 spinulous, an unusually long and strong spine at inner angle. Manus 

 with two rows of four slender spines on upper surface, lower margin 

 spinulous, spines of outer surface arranged in four or five longitudinal 

 rows, inner surface minutely granulous. Fingers spinulous and hairy 

 proximally, horn-colored, teeth and tips almost white. Ambulatory 

 legs very long, slender, long-hairy like carapace and chelipeds; 

 margins of merus and upper margin of carpus and propodus armed 

 with slender spines, those on carpus and propodus nearly normal to 

 the article. 



Measurements. — Female holotype, width of carapace including 

 spines 16, excluding spines 15, width of front including antennal 

 spine 6, length of longest hairs about 6, length of inner spine of carpus 

 of cheliped 2.5 mm. 



Range. — Entrance to Gulf of Mexico, 130 to 184 fathoms. 



Material examined. — 



Off Havana, Cuba; lat. 23° 10' 40" N.; long. 82° 20' 15" W.; 184 

 fathoms; fne. gy. wh. Co.; January 20, 1885; station 2345, Albatross; 

 1 female, holotype (9526); hinder portion missing. 



Yucatan Channel, Mexico; lat. 20° 59' 30" N.; long. 86° 23' 45" 

 W.; 130 fathoms; Co.; January 22, 1885; station 2354, Albatross; 1 

 female, saft shell (18158). 



