PALAEMON. 
PALAEMON. Fair., Latr., Lam., Bose, Leach. 
ASTACUS. Pennant. 
Antennce superior es breviores setis tribus : duabus externis ad basin connatis ; interna breviore, 
inferiores corporis long’itudine, setaceae, decrescentes ; squama magna ad illarum basin. 
Palpi pediformes articulo ultimo penultimo breviore. 
Pedes quatuor antici didactyli ; pari antico minuto ; paria alia simplicia ; unguibus edentulis. 
Abdotnen sex articulatum. 
Cauda pentaphylla ; lamellis duabus externis simplicibus, lamella intermedia spinulis mobilibus 
instructa. 
Upper antennae shortest with three setae, the two external setae joined at their bases, the inte- 
rior one shortest. Under antennae as long as the body, setaceous, decreasing, towards their ex- 
tremities ; with a large squama at their base. Pediform palpi with the last joint shorter than the 
one before it. Four anterior legs didactyle ,* the first pair minute, the other legs simple, 
with simple claws. Abdomen six-jointed. Tail with five lamellae ; the two exterior ones 
simple ; the middle one furnished with little moveable spines. 
The European Palcemones inhabit the shores of the sea during the summer months feeding on 
dead animal matter. The females seem to be much more abundant than the males, and are 
generally found with spawn. 
PAL/EMON SERRATUS. 
Tab. XLIII.---.Fzg. 1—10. 
P. rostro ascendente supra 6, 7 aut 8-dentato apice emarginato ; infra 4, 5 vel 6-dentato. 
Astacus serratus. Penn. Brit. Zool. iv. 19. Pi. 16. fig. 28. 
Palaemon squilla. Latr. Gen. Crust, et Insect, i. 54. 
Leach Edinb. Enci/cl. vii. 401. 
Palaemon serratus. Leach Edinb. Encycl. vii. 432. 
Trans. Linn. Soc. xi. 348. 
Fig. 1. Palaemon serratus mag. nat. 2 et3. Rostri varietates. 4. Antenna superior. 5. 
Antenna inferior. 6. Pedipalpus. 7. Pes antici paris. 8. Pcs secundi paris. 9. Pes tertii 
paris. 10. Unguis. 
This is the common prawn of the London markets. It may always be distinguished from the 
other British species by the form of its rostrum, which, although subject to considerable varia- 
tion in the number of teeth, yet always turns upwards, and has its point generally notched.* It 
has been confounded with the following species by several writers. 
* In two accidental varieties I found the notch wanting, but in three thousand other specimens this character teas constant. 
