764 



ARTHEOPODA 



PHYLUM VII 



Palaeasfacus Bell; and Hoidoixma M'Coy, occur in the Upper Cretaceous of Westplialia, 

 Bohemia and England, the last-named genus also occurring in the Tertiary. More 



doulitfuUy, the Recent 

 genera ■which include the 

 Lobster,^ the Crayfish of 

 Europe, and the Norway 

 Fir.. 1481. Lobster (iVep/iroj3s of Leach), 



Magiu snprajurensi.t have been stated to occur 



(Quenstedt). Upper Jura; j ^^ Upper Cre- 



Chela. taceous. 



Fig. 1480. 



Eryma leptodactylina (Germ.). Litho- 

 graphic Stone 

 (after Oppel). 



Fio. 1482. 



CaUiana!!sa archiaci M. Echv. Turonian ; Montdragon, 

 Var (after Mihie Edwards). 



Fif!. 1483. 



Callimiaxsa untiqua Otto. Turonian ; Turnau, Bohemia. 

 Right chela. 



§ 3. Anomura. 



This section includes forms which have the abdomen generally soft or bent upon 

 itself, with reduced side-plates and tail-fan. They are rare as fossils. The tribe 

 Galatkeidea is represented only by chelae from the Upiaer Cretaceous of Denmark, 

 referred to the Recent Galathea Fabr. Of the tribe Thalassinidea, the Recent 

 genus Gallianassa Leach (Figs. 1482, 1483) is known from the Kimineridgian, as 

 well as from the Cretaceous and Tertiary. Thcdassina Latreille is Tertiary and 

 Recent. The tribe Paguridea, including the Hermit-crabs and their allies, is very 

 doubtfully rejwesented in the Eocene of Hungary by chelae referi'ed to the Recent 

 Pagurus Fabr. The Hippidea are unknown in the fossil state. 



§ 4. Brachyura. True Crabs. 



The true Crabs have the abdomen small, bent under the thorax, and without a 

 tail-fan ; the carapace fused with the epistome at the sides and nearly always in the 

 middle line in front ; the third maxillipeds more or less broad and flattened, covering 

 the other mouth-parts. 



^ The generic name Ilomarus Mihie Edw. is most commonly used for the Lobster, and Astacus 

 Fahr. for the Crayfish. Some writers, however, employ Astacvs Fabr. for the Lobster, and 

 Hotavuihiiis Leach for the European Crayfish. The questions of nomenclature involved cannot suit- 

 ably be discussed here, but reference may be made to a recent ruling (1910) of the International 

 Commission on Zoological Nomenclature. 



