C. Spence Bate on the Peneidea. 187 
diameter of the stalk. Pleon unarmed, sixth somite termi~ 
nating posteriorly in an angle. 
Length about 24 inches. 
Taken in the Atlantic off the coast of South America, at a 
depth of 2650 fathoms. 
Hemipenceus virilis, n. sp. vi Roms 
Rostrum straight, armed with three teeth, posterior small and 
distant. Carapace smooth. Pleon having the posterior 
margin of the fourth and fifth somites produced in the median 
line to a small tooth. Ophthalmopod short, Hye large, 
orbicular. 
Length about 4 inches (male). 
Taken near the Philippine Islands at a depth of 255 fathoms. 
Hemipenceeus dubius, n. sp. 
Rostrum straight, equal in length to the peduncle of the 
first pair of antenne, armed on the lower side with four small 
teeth situated on the distal half, and eight upon the upper, 
equidistant from each other, between the apex and the gastric 
region. Dorsal surface elevated to a crest above the line of 
the frontal margin. Pleon smooth, sixth somite terminating 
in a small tooth posteriorly projected. Hyes large. 
Length about 3 inches (male). 
Taken among the Philippine Islands at a depth of less 
than 20 fathoms of water. 
Genus ARISTEUS, Duvernoy. 
_ This genus was established by M. Duvernoy in the 
Annales des Sc. Nat. for 1841, vol. xv., from a specimen taken 
in the Mediterranean which Risso had previously named 
Penceus antennatus, under the mistaken supposition that the 
structure of the branchiz was essentially different from that 
of Peneus, But although the structure is the same, as pointed 
out by Dana and confirmed by Mr. Miers, the arrangement of 
the branchial plumes is essentially distinct, as may be seen if 
the following Table be compared with that of Pencus. 
Pleurobranchia ............ Tea ya eT Vee Wiis Li eg Wc: 
Arthrobranchiz............ RO Di Oh dseley 
Podobranchia,............. 160 Wad ae a La 
Mastibranchia ............ Qh 711 2) ali i a 3 
Rita t min oyna) 
Tf this Table be compared with that of Peneus, it will be 
found that there are podobranchial plumes attached to the five 
anterior appendages of the pereion (that is, to are pairs 
is 3 
