CLASS I. CRUSTACEA. 
91 
joints : palpi very hairy, the middle joint shortest, the third a little 
longer than the first: four anterior dazes with their tips bent: four 
hinder ones abruptly curved at their base. 
*P- 1. Mac. Pltalangium. Beak acuminate, much shorter than the an- 
tennae: shell behind the rostrum, with three tubercles placed in atri- 
ai }gle, the hinder tubercle largest: arms internally subscabrous and 
hirsute. 
t ancer Phalangium. Penn. Brit. Zool. iv, 8. pi. 0. fig. IT. Macropus 
longirostris. Lair. Gen. Crust, et Insect. Macropodia longirostris. 
Leach, Edin. Lncpcl. vii. — Zool.. Misc. in 18. — Ivans. Linn. Soc. xi. 331. 
- ~~~Mal. Podoph. Brit. tab. 23. 
n habits the mouths of rivers, and is very common in Great Britain. 
D. Abdomen of both sexes four-jointed. Two anterior legs didactyle. 
Fam.IX. LEtrcosiADiE. 
„ Genus 18 . EBALIA. Leach. 
* hel1 rhomboidal, produced in front; the sides entire: anterior pair of 
Lgs depressed, much larger than the rest; arms subangulatcd; fin- 
gers subdeflexed : external, pedipalpcs with their external footstalk li- 
near: abdomen of the male with its last joint at its base furnished 
"ith a dentiform process. 
1 • Lb. Pennantii. Shell granulated, with an irregular elevated cross : 
abdomen with 3 — G joints confluent. 
attcer tuberosus. Penn. Orn. Zool. iv. 8./. 9. A , f. 19. EbuliaPcnnan- 
tii. Leach, Malac. Podoph. Brit. t. tb.f. 1 — 6. & 2 . 
Order II. MACROURA. 
Phis Order contains the Families Pagarii, Palimrini, Astacini, and 
Huillares' of Latreille. 
Division I. — Tail on each side with simple appendices. 
j Earn. I. Pagvridje. Leach. 
ten ; anterior pair largest and dactylc. 
j, Genus 19. PAGURUS. Fair., Latr., Bose, Leach, 
eternal antenna with the second joint of their peduncle with a move- 
able spine affixed to the apex above : abdomen membranaceous : tail 
jhree-jointed, crustaceous ; the second joint on each side appendicu- 
‘ated : f uur [ e g S spurious, short, didactyle. 
The curious economy of the genus Pagurus attracted the attention 
of the ancients. One species is well described by Aristotle. 
AH the species are parasitical, and inhabit the cavities of turbi- 
°ated univalves. They all change their habitation during their 
growth, first occupying the smallestshells, and latterly those of very 
