328 BULLETIX 129, UNITED STATES NATIONAL MUSEUM 



Material examined. — 



MEXICO: LOWER CALIFORNIA 



Dr. Thomas H. Streets, U. S. N.; 1 male (2300), holotype of 

 Libinia semizonale Streets. 



Playa Maria Bay; August 24, 1896; A. W. Anthony; 5 Large males 

 (19523). 



Santa Maria Bay; March 18, 1911; in boat dredge; Albatross; 8 

 young (47113). 



Abreojos Point; July 31, 1922; G. D. Hanna, California Academy 

 Expedition; 7 males, 3 females (Cal. Acad.) ; 1 male, 1 female (56853). 



Off Abreojos Point; lat. 26°.42' 30" N.; long. 113° 34' 15" W.; 

 5}4 fathoms; gn. M.; May 4, 1888; station 2835, Albatross; 1 young 

 female (21917). 



Magdalena Bay; May 2, 1888; Albatross: Lat. 24° 38' 00" N. ; long. 

 112° 17' 30" W.; 51 fathoms; gn. M.; temp. 56.4° F.; station 2832; 2 

 young (21915). Lat. 24° 38' 00" N.; long. 112° 17' 30" W.; 51 

 fathoms; gn. M.; station 2833; 2 young (21916). Lat. 24° 32' 00" 

 N.; long. 111° 59' 00" W.; 12 fathoms; fne. gy. S.; station 2831; 19 

 young (21914). 



Magdalena Bay: 1917; C. R. Orcutt; 1 male (50628). Hassler Ex- 

 ped.; 1 young female (1871, M. C.Z.). 



LIBINIA MEXICANA Eathbun 



Plate 244, fig. 1 



Libinia mexicana Rathbun, Proc. U. S. Nat. Mus., vol. 15, 1892, p. 242, 

 pi. 31, fig. 3 (type-locality, Gulf of California, station 3029, Albatross; 

 holotype, Cat. No. 16072, U.S.N.M.). 



Diagnosis. — Carapace of young with 12 long spines behind the or- 

 bits. Median spines 6. A long hepatic spine. 



Description of young male. — Pubescence short, stout, vesicular. 

 Carapace pyriform, much narrower (exclusive of spines) than the 

 postfrontal length. Median spines 6: 2 gastric, long, 1 genital, short, 

 2 cardiac, the anterior short, posterior long, and 1 intestinal, long. 

 Two long marginal spines, 1 hepatic, 1 branchial and a small spinule 

 or tubercle on the postlateral margin. A short gastric spine either 

 side of the anterior median spine; 2 long dorsal branchial spines 

 arranged in an obliquely longitudinal line. Preocular eave armed 

 with a rather long, suberect spine. Rostrum horizontal, slightly con- 

 stricted at middle, horns occupying nearly half its length, tapering, 

 acute. Two pterygostomian protuberances, the anterior a conical, 

 acute spine, the posterior a tubercle. A sharp conical spine occupies 

 the anterior margin of the basal antenna! segment. An open sinus 

 in lower margin of orbit. 



