PENAUS. 
PENAUS. Fabr., Latr., Bosc, Leach. 
Antenne superiores breviores basi appendiculati : apice setis duabus aqualibus ; seta superiore 
inferné excavata. 
inferiores corporis longitudine, setacee, decrescentes ; squama magna ad illarum basin. 
Palpi pediformes articulis quinque exsertis ; articulo ultimo obtusiusculo. 
Pedes basi appendiculati: sex antici didactyli; alii simplices ; unguibus edentulis. 
Abdomen sex articulatum. - 
Cauda pentaphylla ; lamellis duabus externis simplicibus ; lamella media apicem versus utrinque 
spinulis mobilibus instructa. 
Upper antenne shortest with an appendage at their base ; apex with two equal sete ; upper 
seta excavated below. Under antenne as long asthe body, setaceous, decreasing towards their 
extremities, with a large broad squama at their base. Pediform palpi with five exserted 
joints, the last joint obtuse. Legs with a little appendage at their base: six anterior legs 
didactyle, the other legs simple, with toothless claws. Abdomen six-jointed. Tail with five 
Jamelle ; the two extettial lamella simple, the middle lamella towards its apex furnished with 
little moveable spines. 
PENAEUS TRISULCATUS. 
Tas. XLII. 
P. thorace postice trisulcato ; rostro decendente supra multi-dentato. 
Squilla Crangon. Rondel. xviii. 547. vive. 
Peneus trisulcatus. Leach Trans. Linn. Soc. xi. 347. 
Fig. 1. Penzus trisulcatus mag. nat. 2. Antenna superior. 3. Antenna inferior. 
A. Pedipalpus. 5. Pes anticiparis. 6. Pes secundi paris. 7. Tertii paris. 8. Quarti paris. 
9. Quinti paris. 10. Cauda. 
Peneus trisulcatus which is the only British species yet discovered, was sent to Mr. Sowerby 
by the Rev. H. Davies, who caught it on the shore of Anglesea. I have likewise received a 
specimen from the coast of RVs. 
The fourth and fifth segments of the abdomen are notched on each side. 
