DESCRIPTION OF GENERA AND SPECIES. 



ANOMURA. 



Anomoures, Milne-Edwards, Ann. d. Sci. Nat., ser. 1, t. xxv. p. 298, 1832. 



„ Milne-Edwards, Hist. Nat. des Crust., t. ii. p. 163, 1837. 



Anomala, De Haan, Crust. Japonica, p. 195, 1850 {fart). 

 Anomoura, Dana, U.S. Explor. Exped., vol. xiii.. Crust., part i. p. 398, 1852. 

 Bell, Brit. Crust., p. 163, 1853. 



,, Stimjison, Proc. Acad. Nat. Sci. Philad. p. 63, 1858. 



,, Miers, Catal. New Zealand Crust., p. 56, 1876. 



„ Haswell, Catal. Austral. Crust., p. 138, 1882. 



Anomura, Heller, Crust, siidlichen Europa, p. 142, 1863. 



Cephalothorax always more strongly developed than the abdomen. Carapace broad or 

 elongate ; frontal region with in most cases a projecting rostrum which unites below with 

 the antennular sternum ; orbits and antennular fossae seldom present. Antennules and 

 antennae well developed, the latter usually situated externally to the eyes and with long 

 flagella. Outer maxillij)edes elongated and pediform, more slender than in the Brachyura. 

 Last thoracic segment often free and not fused with the preceding segments. Thoracic 

 sterna usually broad in front, narrowed posteriorly, without a median apodeme. The 

 three anterior pairs of legs well developed, the fifth pair (frequently also the fourth) 

 slender and of small size, prehensile, or folded in the branchial chambers. Abdomen 

 bent under the carapace or extended. Genital openings of the females placed on the 

 basal joints of the third pair of legs. Branchiae nine or more in number on each side. 



The Anomura are found in all seas, but much more abundantly in those of tropical 

 or temperate climates ; a few forms are terrestrial or fluviatile (Birgus, Ccenohita). The 

 majority inhabit shallow water or moderate depths ; two groups, however — the Pagurids 

 and the Galatheids — are numerously represented in the abysses of the ocean ; all are 

 true bottom-living forms. 



Our knowledge of the existence of Anomura in former geological ages is very 



(ZOOL. CHALL. EXP. — PART LXIX. — 1887.) ZzZ 1 



