tance between postorbitcal margin and hepatic 

 spine. Antennal carina very prominent. Cervical 

 sulcus 14 to 1^ C.I., ending slightly anterior to mid- 

 length of carapace. Hepatic carina % to l^ c.l., 

 sharp, sloping anteroventrally to end Yi^ to Yoq c.l. 

 from anterior margin of carapace. Antennal sjiine 

 prominent and acute ; hepatic spine pronounced. 



ANTENNULES 



Lateral flagellum about three-quarters of 

 length of antennular peduncle, slightly longer and 

 with articles shorter than median flagellum; an- 

 terolateral spine sharp; stylocerite acuminate, 

 reaching slightly beyond midlength of first an- 

 temaular segment. Prosartema reaching distal end 

 of proximal fifth of second antennular segment. 

 ANTENNAE 



Length of scaphocerite 21/4 times maximum 

 width, its length relative to carapace length de- 

 creasing slightly with growth ; spine reaching dis- 

 tal end of antennular peduncle or to distal end of 

 proximal quarter of thickened portion of dorsal 

 flagellum. Carpocerite I14 times longer than wide, 

 reaching distal end of optic peduncle. Antennal 

 flagellum relatively short, about ly^ body length. 



THORACIC APPENDAGES 



Third maxilliped reaching at least distal one- 

 third of second and, at most, distal end of third 

 antennular segment ; longer in larger individuals. 

 Length of dactyl % to % that of propodus. First 

 pereopod surpassing carpocerite by half length of 

 dactyl or by entire lengtii of propodus. Second 

 pereopod surpassing carpocerite at least by entire 

 length of propodus and, at most, by one-half length 

 of carpus. Third pereopod exceeding antennular 

 peduncle by one-half length of dactyl or by one- 

 eighth length of carpus. Fourth jaereopod surpass- 

 ing carpocerite by one-half length of dactyl to 

 three-quarters length of propodus. Fifth pereopod 

 subequal in length to fourth. Exopods on all pereo- 

 pods ; long ischial and basial spines on first pereo- 

 pod ; rather long basial spine on second pereopod. 

 ABDOMEN 



Carinate dorsally from posterior half of fourth 

 somite posteriorly, carina increasing in lieight 

 progressively from base to keel on sixth somite, 

 there ending in sharp spine on posterior margin. 

 Dorsolateral sulcus characteristically broad (fig. 

 33), ratio between height of keel and width of 

 sulcus ranging from about 0.25 to 3, modally 1.75 

 (fig. 34) ; K/S mode 1.75 in size classes 16 to 36 



Figure 32. — Pcnaeus (M.) duorarum 

 notialis P^rez Farfante. Cephalo- 

 thorax, holotype, S 41.5 mm. c.l., off 

 Las Piedras, Gulf of Venezuela. 



522 



U.S. FISH AND WILDLIFE SERVICE 



