tober 5, 1965, Oregon Sta. 5664, lat. 11°44' N., 

 long. 70°22' W.)- 



Taxonomic Remarks 



Questions have arisen concerning the identity 

 of P. duorarum from tropical West Africa. Bur- 

 kenroacl (1939) identified the specimens from that 

 region as P. duorarum "Form B,'' the same as 

 "candied shrimij" from the Caribbean region and 

 the Atlantic Coast of Soutli America. My studies 

 also indicate that the specimens of P. duorar-wm 

 from both regions shoidd be referred to P. d. 

 notialis. On the basis of biometric studies Kossig- 

 nol and Eepelin (1962) conchided tliat there are 

 two different populations of this slirinip in West 

 Africa : one population along tlie coast of Cameron 

 has shrim}) with the third pair of pereopods longer 

 than they are in the other jiopulation that ranges 

 along "la cote du Congo et du Sud Gabon." They 

 considered the northern population a different 

 variety and named it "cameronensis."' This varietal 

 name does not have priority over notialis because 

 under the International Rules of Zoological 

 Nomenclature, a new name published after 1960 

 as a variety is to be regarded as of infrasubspecific 

 rank. In the eastern Atlantic P. d. notialis ranges 

 both west to Cap Blanc and south to Angola be- 

 yond the areas considered by Eossignol and 

 Repelin. 



Study Material 



For a list of records see Perez Farfante, 1967. 

 Additional records follow. 



MEXICO 



Quintana Roo :2s, USNM, Punta Niccheha- 

 bin, Bahia de la Ascension, less than 1/3 fm., 

 April 13, 1960, F. C. Daiter, Smithsonian- Bredin 

 Exped. Sta. 65-60. 

 COLOMBIA 



1 S , USISTM, off Punta Broqueles, 400 fm., Ore- 

 gon Sta. 4902, May 28, 1964. 



Diagnosis 



Adi-ostral sulcus broad posteriorly, and long, 

 reachmg almost to posterior margin of carapace. 

 Median sulcus long, ending immediately anterior 

 to jxisterior end of adrostral sulcus, and deep 

 along its entire length. Doreolateral sulcus broad. 

 Petasma with distal portion of ventral cost a broad- 

 ening and turning proximally rather abruptly. 



armed with minute spines along free border and 

 with compact group of large teeth on attached 

 border; apex of ventral costa adnate to adjacent 

 wall; distal fold small, imanned or with few sub- 

 marginal spinules. Thelycum with apical process 

 relatively large, and with prominent, short, imdi- 

 vided median carina on broad posterior process; 

 carina exposed owing to slight divergence of an- 

 teromedian comers of lateral plates. 



ROSTRUM 



Description 



7-9 



Teeth - — , mode -— (percentage distribution: 

 U — Ji ^ 



8/2—61, 9/2—30, 8/1—4, 7/2—3, 7/1—1, 9/1— 



0.33, 7/0—0.66; N = 300) -f epigastric; position of 



ventral teeth variable, first tooth situated from 



well anterior to slightly posterior to last dorsal 



tooth; rostrum relatively short in larger juveniles 



and subadults, reaching at most to distal end of 



antennular peduncle; attaining maximum length 



in relation to carapace length at 12 to 18 mm. 



rl 

 c.l. (ratio — r as high as 0.75); decreasmg pro- 

 gressively with increasing length of shrimp, 

 rostrum reaching distal end of second antennular 



r.l. 

 segment in shrimp 50 mm. c.l. (ratio ^ reduced 



to about 0.40); rostrum straight apically, oc- 

 casionally upturned, convex proximally; highest 

 portion of blade at level of third dorsal tooth; 

 latter level with anterior margin of carapace; 

 rostrum tip )i to M r-1- Postrostral carina 

 strong, prominent, and uniform in width or 

 slightly wider in anterior half, and long, extending 

 almost to posterior margin of carapace. Median 

 sulcus deep throughout, long, ending near posterior 

 margin of carapace. Adrostral sulcus deep, broad 

 posteriorly, Yf, to 1^ width of postrostral carina, 

 and rather long, ending \){x to iK, c.l. from posterior 

 margin of carapace. Adrostral carina prominent 

 and long, same length as adrostral sidcus. 

 CARAPACE (fig. 32) 



Length in proportion to total length smaller in 

 juveniles, increasing abruptly at about subadult 

 stage. Gastrofrontal sulcus broad, extending 

 posteriorly to about one-fifth c.l.; gastrofrontal 

 carina sharp, turning slightly posterodorsally and 

 ending in acute orbital angle anterioi-ly. Orbito- 

 antennal sulcus wide anteriorly, narrowing pos- 

 teriorly to below apex of hepatic spine, there 

 widening into base of spine. Gastro-orbital carina 

 high and sharp, occupying posterior % to % of dis- 



WESTERN ATLANTIC SHRIMPS OF GENUS PENAEVS 



521 



