170 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. [1885. 



Station 2143, March 23, 1884; Gnlf of Darien; north latitude 9° 30' 

 45", west longitude 76° 25' 30"; 155 fathoms, green mud. One female 

 (6939). 



New Haven, Conn., April 29, 1885. 



ON SOME GENERA AND SPECIES OF PENiEIDiE, MOSTLY FROM 

 RECENT DREDGINGS OF THE UNITED STATES FISH COMMIS- 

 SION. 



By SIDIVEV I. SJTIITa. 



Penaeus Fabricius (restricted). 



Unfortunately I have not been able to examine either of the species 

 referred to the genus by Fabricius, but in P. carimonte^ canaliculatus, 

 BrasiliensiSj semisulcatus, setifenis, and styUrostris the antennular fla- 

 gella are very short; the distal segment of the mandibular palpus is 

 much larger than the proximal, very broad, and not prolonged into a 

 narrow tip ; the endognath of the first maxilla is greatly elongated and 

 segmented; the endopod of the maxilliped is slender and composed of 

 four segments, and the exopod is lamellar and unsegmented ; both pairs 

 of gnathopods have well-developed epii)ods and large exopods; all the 

 peraeopods have small exopods, but only the first, second, and third are 

 furnished with epipods ; there is a well-developed pleurobranchia on 

 the fourteenth somite. The number and arrangement of the branchiaB 

 and epipods are the same for all these species, and is indicated in the 

 following formula: 



These species also agree in having well-developed antennal and hepatic 

 spines and conspicuous antennal and hepatic sulci ; but these charac- 

 ters are not regarded as of generic value. 



Parapenaeus, gen. uov. 



The species referred to the genus here proposed are at once distin- 

 guished from the species of Penceus proper in having the endognath of 

 the first maxilla short andunseguieuted, the second gnathopod without 

 an epipod, and the fourteenth somite (posterior somite of the peraeon) 

 wholly without brauchiiB. The species examined further agree in hav- 

 ing none of the sulci of the carapax conspicuous except the cervical, 

 and in having the antennular flagella shorter than the carapax. In 

 the first three species hei^e referred to the genus the mandibular palpi 



