670 CLASS X. 



middle of the shell, and this is very broad, and incised deeply on each side. 

 They form the genus Ibacus LEACH ; to it belongs Scyllarus antarcticus 

 FABR., KUMPH. 1. 1. fig. c. 



Family XXX. Anomura (Anomala LATR.). Four antennae 

 inserted nearly in the same transverse row, or middle superior; 

 external antennas without scale at the base. Eyes placed on a 

 petiole, very often elongate. Two or four posterior feet less by far 

 than the rest. Abdominal feet imperfect, small, deficient in some 

 of the segments. Lateral appendages of penultimate segment of 

 abdomen reflected at the sides, never composing a flabelliform 

 pinna. 



Phalanx I. Pagurina (Paguridce BELL). First pair of feet 

 didactylous, chelate. Appendages of penultimate segment of abdo- 

 men short, composed mostly of two parts, incurved, inserted on 

 a short peduncle, not foliaceous. Integuments of abdomen often 

 soft; membranous. 



Pagurus DALD., FABR. Abdomen contorted, membranous, sup- 

 plied with thin calcareous laminae scattered in the back. Fourth 

 and fifth pairs of feet very short, subequal. 



Pagurus LATK. Middle antennae short, with two very short 

 terminal setae. 



Sp. Pagwrus Bernhardus FABR., Cancer Bernhardus L., SWAMMERDAM 

 Bijbel der Nat. Tab. xi. DESMAR. Crust. PL 30, fig. 2, the hermit-crab ; 

 lives in different turbinated shells, when full-grown in the shell of Buc- 

 cinum undatum. 



Note. Add genus Cancellus EDW. 



Compare MILNE EDWARDS Observations sur les Pagures, &c., Ann. des 

 Sc. nat. 2e SeVie vi. 1836, Zool. pp. 257 288, PI. 13, 14; ejusd. Sur 

 quelques nouvelles especes du genre Pagwe, Ann. des Sc. nat. sieme Se'rie x. 

 1848, Zool. pp. 59 64. 



Ccenobita LATR. Middle antennae long, with peduncle elongate 

 and two unequal setae, one of them long. 



Sp. Ccenolita Diogenes LATR., Encycl. meih., Crust. PL 284, figs, a, 3, 

 EDWARDS Hist. nat. des Crust. PL 22, figs, ri 13. 



Birgus LEACH. Abdomen broad, covered above by a tabulate 

 calcareous crust, membranous below. Fourth and fifth pairs of 



