ing well anterior to posterior margin of carapace. 

 Adrostral sulcus broad posteriorly from same to 

 twice width of postrostral cariiia, and long, ending 

 )i2 to Mo c.l. from posterior margin of carapace. 

 Adrostral carina prominent and long, same length 

 as adrostral sidcus. 



CARAPACE (fig. 61) 



Gasitrofrontal sulcus broad, rather deep, ex- 

 tending to about one-fifth c.l.; gastrof rental ca- 

 rina pronounced. Orbito-antennal sulcus slightly 

 less than one-third c.l., wide anteriorly, narrow- 

 ing posteriorly to below apex of hepatic spine, 

 there widening again into base of spine. Gastro- 

 orbital carina pronounced, sharp and long, oc- 

 cupying % to % distance between postorbital 

 margin and hepatic spine. Antemial carina very 

 prominent. Cervical sulcus Vs to 14 c-1-? ending 

 slightly anterior to midlength of carapace. He- 

 patic carina sharp, sloping anteroventrally to end 

 Vie to 1/^0 c.l. from anterior margin of carapace. 

 Antennal spine prominent and acute ; hepatic spine 

 very pronounced. 



ANTENNULES 



Lateral flagellum relatively long, two-thirds 

 length of antennular peduncle, slightly longer than 

 median flagellum and with articles shorter than 

 those of median flagellum; anterolateral spine 

 sharp; stylocerite very acute, reaching midlength 

 of first antennular segment. Prosartema reaching 

 proximal one-sixth of second antennular segment. 



ANTENNAE 



Scaphocerite length 21/2 times width at base; 

 spine reacliing distal end of antennular peduncle. 

 Cai-pocerite length I14 width, its distal end reach- 

 ing base of eye. Antennal flagellum short, 1% 

 body length. 



THORACIC APPENDAGES 



Third maxilliped reaching approximately distal 

 end of first antennular segment ; length of dactyl 

 % to % that of propodus. First pereopod reaching 

 at least to distal end of carpocerite, but not ex- 

 ceeding it by more than three-quarters length of 

 dactyl. Second pereopod surpassing carpocerite by 

 entire length of dactyl or four-fifths that of pro- 

 podus. Third pereopod reaching at least to distal 

 tliird of second but not beyond distal end of third 

 antemiular segment. Fourth pereopod reaching 

 distal end of carpocerite or surpassing it by one- 

 half length of dactyl. Fifth pereopod extending 

 anteriorly one-quarter dactyl length beyond 



Figure 61. — Petweus (Af.) paul- 

 cnsis P^rez Farfante. Cephalo- 

 thorax, holotyije, $ 35 mm. c.l., 

 Santos, Sao Paulo, Brazil. 



WESTERN ATLANTIC SHRIMPS OF GENUS PENAEUS 



557 



