» 
348 Dr. Lracu’s Arrangement of the Crustacea, óc. 
SUBDIVISIO À. 
Antenne eateriores infra interiores inserte ; ; interiores setis tribus. 
Cauda lamellä exteriore unipartitä. 
Gen. 19. Parzumon, Fabr., Latr., $c. 
Astacus, Penn. 
Cancer, Linn. dopage 
Pedes quatuor antici didactyli, pari antico minore. Palpi pedi- 
formes articulo ultimo penultimo breviore. 
Spec. 1. Palemon serratus. 
P. rostro ascendente supra 6- 7- aut 8-dentato apice emargi- 
nato ; infra 4- 5- vel 6-dentato. 
Astacus serratus. Penn. Brit. Zool. iv. 19. pl. 16. fig. 28. 
Palemon Squilla. Latr. Gen. Crust. et Insect. i. 54. 
Habitat in Mari Britannico. | 
Spec. 2. Palemon Squilla. 
P. rostro recto apice emarginato. supra 7- aut 8- infra 2- vel 
3-dentato. | 
Cancer Squilla. Linn. Syst. Nat. i. 1051. 
Habitat cum precedente in Danmoniá australi vulgate. 
Linnzus, in the second edition of Fauna Suecica, thus describes 
the above species: “ Thorace levi rostro supra serrato ; subtus 
3-dentato, manuum digitis aqualibus.”—* Rostrum lanceolatum 
perpendiculare, acutum, supra octo-crenis, infra tribus serratum ; 
manus, que tertio pedum pari insident, digitis sunt equalibus.” 
In the last edition of Systema Nature this character is again re- 
peated ; and as it applies exactly to the most frequent variety of 
this species, there cannot be the least doubt as to the correct- 
ness. 
