forming large auricle; ventral costa with apex 

 free. Lateral plates of thelycnm with antero- 

 medial corners extended anteriorly forming- 

 two projections which cover posterior process 



P. {M.) hrasUiensis Lat. (p. 562) 



Petasma with distomedian projection rela- 

 tively short, distal fold not forming auricle; 

 ventral costa with apex attaclied to adjacent 

 membranous portion. Lateral plates of thely- 

 cum with anteromedial corners not extended; 

 posterior process exposed i 



4. Petasma with distal portion of ventral costa 



armed along free border with minute spines, 

 broadening and turning proximally ratlier 

 abruptly. Lateral plates of thelycum with 

 anteromedial corners slightly divergent; 

 iwsterior process with undivided median 



carina 5 



Petasma with distal portion of ventral costa 

 unarmed along free border, almost straight or 

 arc-shaped, gradually broadening and grad- 

 ually turning proximally. Lateral plates of 

 thelycum with anteromedian corners widely 

 divergent; posterior process with median 

 carina bifurcate anteriorly 6 



5. Dorsolateral sulcus narrow, ratio between keel 



height and sulcus width (measured at about 

 one-third of somite length from posterior 

 margin) usually more than three, sulcus often 



almost closed P. (M.) 



duoraruin duorariim Burkenroad (p. 499) 



Dorsolateral sulcus broad, ratio between keel 



height and sulcus width usually less than 



three __— P. (31.) 



duorarum notialis Perez Farfante (p. 520) 



6. Adrostral sulcus long, almost reaching posterior 



margin of carapace, deep and broad posteri- 

 orly, % to 2 times width of postrostral carina 

 (measured at posterior one-eighth of distance 

 from posterior end of adrostral sulcus to epi- 

 gastric tooth) 7 



Adrostral sulcus relatively short, never ap- 

 proaching posterior margin of carapace, shal- 

 low and narrow posteriorly, % to % times 



width of postrostral carina P. 



(M.) aztecufi suhtilis Perez Farfante (p. 546) 



7. Median sulcus long and deep along entire 



length. Dorsolateral sulcus broad, ratio be- 

 tween height of keel and sulcus width usually 

 less than three. Petasma with distal portion 

 of ventral costa tajjering to i)oint, arc shaped, 



4m 



and armed with elongated group of closely set 

 teeth on attached border. Thelycum with an- 

 terior and posterior processes broad 



P. (31.) aztecus aztecus Ives (p. 527) 



Median sulcus short, shallow and often inter- 

 rupted. Dorsolateral sulcus narrow, ratio 

 between height of keel and sulcus width 

 usually more than three, sulcus often almost 

 closed. Petasma with distal portion of ven- 

 tral costa blunt, almost straight, and armed 

 with irregularly arranged teeth. Thelycimi 

 with anterior and posterior processes nar- 

 row 



-^P. (M.) paiilcwiis Perez Farfante (p. 555) 



Penaeus (Litopenaeus) setiferus 

 (Linnaeus) 



Fig\ircs 4 to 13 



United States: white shrimp, grey shrimp, lake 

 shrimp, green shrimp, green-tailed slirimp, blue- 

 tailed shrimp, rainbow shrimp, Daytona shrimp, 

 common shrimp, and southern shrimp. Mexico: 

 camaron bianco. 



/isfacux furiafUh. Americamcs Seba, 1759: 41, pi. 

 17, fig. 2; [fide] Holthuis, 1962: 115, 116; [fide] 

 Holthuis, 1964a: 227, 228; [fide] Holthuis, 

 1964b: 233. 

 Cancer setiferus Linnaeus, 1767: 1054, 1055 (neo- 

 type, designated by Burkenroad, 1939, <J , YPM 

 4385— BOC 237 =— otf Matanzas Inlet, Fla., 8 to 

 10 fm., April 2, 1934, M.B. Bishop) ; Houttuyn, 

 1769: 434, 435; Miiller, 1775: 1133; [fide] Hol- 

 thuis, 1962: 115, 116; [fide] Holthuis, 1964a: 

 227-229; [fide] Holthuis, 1964b; 232-234; In- 

 ternational Commission on Zoological Nomen- 

 clature, 1967 : 151, 152. 

 ? Cancer {Gammarellus) setiferm: Herbst, 1793: 



106, 107, pi. 34, fig. 3. 

 ?Pen.aeuJ^ orhignyanus Latreille, 1817 : 155. 

 Penaeus fuviatilis Say, 1818: 236, 238; Gunter, 

 1962a: 109-112; Gunter, 1962b: 121; Gunter, 

 1962c: 216-224, 226; Gunter, 1963: 103-108; 

 Gunter and Hall, 1963: 295, 297, 304; Gunter, 

 1964: 229; Gunter, Christmas, and Killebrew, 

 1964: 181-185; [fide] Holthuis, 1964a; 227; 

 [fide] Holthuis, 1964b: 233, 234; Ingle, 1964: 



-'The referpiices made to s|iecimens in the literature under the 

 Bingham Oceanographic Collection catalog numbers are men- 

 tioned here with file initials BOC. This collection is in the Pea- 

 body Museum of Natural History, Yale University. 



U.S. PISH AND WILDLIFE SERVICE 



