338 BULLETIN 129, UNITED STATES NATIONAL MUSEUM 



MAIOPSIS PANAMENSIS Faxon 



Plate 247 



Maiopsis panamensis Faxon, Bull. Mus. Comp. ZooL, vol. 24, 1893, p. 151 

 (type-locality, station 3355, Albatross, 182 fathoms; holotype. Cat. No. 

 4480, M. C. Z.); Mem. Mus. Comp. ZooL, vol. 18, 1895, p. 13, pi. 2. 



Z)m(7/io.9?"s.^ Carapace thickly covered with spines. Eyestalks 

 slender; orbits with 2 deep fissures above. Basal segment of antennae 

 very broad, and with 3 anterior spines. 



Descri'ption.^DoTssil surface of carapace thickly set with spines of 

 various sizes and scattered hooked setae. Spines distributed as fol- 

 lows: 5 on the gastric region, 1 on the genital, 1 on the cardiac, 4 on 

 the intestinal, and about 7 on each branchial region. Margin of 

 carapace armed with 12 prominent spines, 3 of which are on the 

 hepatic region. Chelipeds and legs covered with numerous spiny 

 tubercles; meri armed with 3 or more prominent spines at distal end. 

 Chela long and slender, tubercles of hand smaller than on other parts 

 of legs; fingers nearly smooth; a deep pit at base of movable finger. 

 Sternum ornamented with small tubercles along each side of abdo- 

 men. First abdominal segment furnished with a bidentatr^ tubercle. 

 (Faxon.) 



Measurements. — Male, holotype, length from base of rostrum to 

 posterior margin of carapace, 112; width 113.5; length of rostrum 22, 

 length of horns 11, width between eyebrows 38, length of cheliped 

 156 mm. 



Range. — Known only from the unique specimen dredged in the 

 Bay of Panama; lat. 7° 12' 20" N.; long. 80° 55' 00" W.; 182 fath- 

 oms; bk. G. Sh.; temp. 54.1° F.; Feb. 23, 1891; 1 male (Cat. No- 

 4480, M. C. Z.). 



Genus PARAMITHRAX Milne Edwards 



Paramithrax Milne Edwards, Hist. Nat. Crust., vol. I, 1834, p. 324 

 (part: §A); type, P. peronii Milne Edwards. — Miers, Journ. Linn. Soc. 

 London, vol. 14, 1879, p. 655 (part: subgenus Paramithrax, restrict- 

 ed). — Rathbun, Biol. Results "Endeavour," 1909-14, vol. 5, part 1, 

 1918, p. 17. 



Carapace oblong-triangular, usually spinous above. Rostrum 

 composed of two spines divergent from their base. Orbits large, deep, 

 oval, with a forward aspect, incomplete below, upper margin promi- 

 nent, with two deep fissures and long spines. The eyes when re- 

 tracted are concealed; stalks rather long, slender, curved, corneae small. 

 Postorbital spine conical, usually remote from orbit so that the eye 

 does not touch it. Basal article of antennae much enlarged, armed 

 with spines; movable portion arising within orbital margin and 

 separated from the cavity of the orbit by a narrow process of the 

 basal article. Anterior margin of buccal cavity straight or nearly so. 



