70 



BtTLLETIN 152, "UNITED STATES NATIONAL MUSEUM 



Range. — Galapagos Islands. 



Material examined. — Reef Ni of Tagus Hill, Tagus Cove, Albemarle 

 Island; March 16, 1889; Stanford Galapagos Expedition; 1 male 

 holotype, 1 young (24833), 1 male, 2 young (Stanford Univ.). 



1888; Albatross: Albemarle Island; April 10; 1 young female 

 (22033). April 7; off Hood Island: Lat. 1° 21' 30" S., long. 89° 39' 

 45" W.; 20 fathoms; co. S.; station 2812; 1 young male (22031). 

 Lat. 1° 21' 00" S., long. 89° 40' 15" W.; 40 fathoms; co. S.; station 

 2813; 5 males, 8 females (22032). 



PORTUNUS (ACHELOUS) ANGUSTUS Rathbun 



Plate 32 



Porlunus (Achelous) angusius Rathbun, Proc. U. S. Nat. Mus., vol. 21, 1898' 

 p. 594, pi. 44, fig. 2 (type-locality, off Hood Island, Galapagos, 20 fathoms' 



station 2812, Albatross; type. Cat' 

 No. 21587, U.S.N.M.); Proc' 

 Washington Acad. Sci., vol. 4' 

 1902, p. 282. 



Diagnosis. — An tero - lateral 

 teeth very unequal, four small 

 ones, lateral tooth very short. 

 One spine at postero-distal 

 angle of merus of swimming 

 feet. 



Description. — Closely re- 

 lated to P. (A.) hrevimanus. 

 Carapace narrower, branchial 

 ridges stronger, front more 

 advanced, outer teeth broader 

 at base than inner teeth from which they are separated by sinuses 

 wider than the median sinus. Antero-lateral teeth alternately large 

 and small, the second, fourth, sixth, and eighth teeth distinctly 

 smaller than the others, as in Cronius, the ninth or lateral tooth or 

 spine very little longer than the seventh. Inner suborbital tooth 

 equally advanced with the second pair of frontal teeth. Outer spine 

 of wrist smaller than in hrevimanus. Merus of natatory feet more 

 than half again as long as wide; postero-distal angle armed with a 

 sharp spine. This is true of the two young specimens (25671) and 

 of the left merus of the type female; the right merus of the type shows the 

 base of a spine which has been broken and formed two small denticles. 

 Measurements. — Female holotype, total length of carapace 25.5, 

 width of same 37.2, width to anterior base of lateral spine 33.5, 

 fronto-orbital width 21, width of front 7.2 mm. 

 Range. — Galapagos Islands. 



Material examined. — Reef N. of Tagus Nill, Tagus Cove, Albemarle 

 Island; March 16, 1899; Stanford University Expedition; 2 young 

 (Stanford Univ.), 2 young (25671). 



Figure 12.— Portunus (Achelous) angustus, female, 

 holotype, carapace 37.2 mm. wide, dorsal view 



