CLASS I. CRUSTACEA. 



91 



joints: jinlpi very hairy, the middle joint shortest, the third a little 

 longer than the first: /««?■ anterior claws with their tips hent: /y«r 

 hinder ours aliniptly curved at their base. 



Sp. 1. Mae. Vlmlaji<iiiun. ik-ak acimiinatc, much shorter tlian the an- 

 tenna' : slicll beliiiid the rostrum, with three tubercles placed in a tri- 

 angle, the hinder tubercle largest: arms internally subscabrous and 

 hirsute. 



Cancer Phalangium. ram. Brit. Zool. iv. 8. pi. 9. Jig. 17. Macroptis 

 longirostris. iMtr. Gen. Crust, et Insect. IVIacropodia longirostris. 

 J^ach, Edin. Enci/cl. \\i. — Z(wl. Misc. ii. 18; — Trans. Linn. Soc. xi. 331. 

 —Mai. Fodoph. Brit. tab. 23. 



Inhabits the mouths of rivers, and is very common in Great Britain. 



p. Abdomen of both sexes four-jointed. Two anterior legs didactyk. 



Fam.IX. Leucosiad.e. 

 Genus 18. EBALIA. Leach. 



Shell rhomboidal, produced in front; the sides entire: anterior pair of 

 /c^.s depressed, much larger than the rest; arms subangulatcd ; fin- 

 gers subdctlexed : external pedipulpes with their external footstalk li- 

 near: abdomen of the male with its last joint at its base furnished 

 with a dentiform ])roccss. 



Sp. 1. Eb. Pennantii. Shell gramdated, with an irregular ele\ated cross : 

 abdomen with 3 — G joints confluent. 



Cancer tuberosus. Penn. Orn. Zool. iv. 8.^. 9. A./. 10. Ebalia Pennan- 

 tii. Leach, Malar. Podoph. Brit, t.'iii.f 1—6. ^ ik, Q . 



Order II. MACROURA. 



This Order contains the Families Pagurii, Palinurini, Astacini., and 

 Sc^uillares of Latreille. 



Division l.— Tail on each side with simple appendices. 



Fam. I. Pagurid.1. Leach, 

 Legs ten ; anterior pair largest and dactyle. 



Genus 19. PAGURUS. Fabr., Latr., Base, Leach. 

 Erfer-nal antenna with the second joint of their peduncle with a move- 

 able spine affixed to the apex above: abdomen membranaceous: tail 

 tliree-jointed, crustaceous; the second joint on each side appendicu- 

 lated : four hinder legs spurious, short, didactyle. 



The curious economy of the genus Pagurus attracted the attention 

 of the ancients. One species is well described Vjy Aristotle. 



All the species are parasitical, and inhabit the cavities of turbi- 

 nated univalves. They all change their habitation during their 

 growth, first occupying the smallest shells, and latterly those of very 



