ARTHROPODA 



PHYLÜM VII 



-, rr 7 • M^nr^^r nppnrin tlieUDPei'Cretaceousof Westplialia, 

 Palaeastacus Bell ; and H<^,lopar«, M<.oy omr in the L pp ^ ^^ ^^^^^ 



lioliemia and England, the last-named genus also ''-''''"^uUinDy, the Eecent 



geiiera which include the 



Lübster/ the Crayfish of 



Eiirope, and the Norway 



Fio. 1481. Lobster {Nephroms of Leach), 



Magih, " suwajurensis have beeil stated to occiir 



(Quenstedt). Upper Jura; ^^ e^rlv as the Upper Cre- 

 Söflingen, Würteinberg. -^ 



d 



Chela. 



taceoiis. 



Fk;. 1482. 



Callianaffsa arcUaci M. Edw. Tnronian ; Montdragon, 



Var (after Milne Edwards). 



Fia. 1480. 



Eryma leptoiiactyliTia (Germ.). Litho- 

 graphie Stone ; Solenhofen, Bavaria. i/i 

 (after Oppel). 



Callimiassa antiqua Otto. Turonian ; Turnau, Bohemia. 

 Eight chela. 



§ 3. Anomura. 



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

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

 Galatheidea is represented only by chelae from the Upper Cretaceous of Denmark, 

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

 geniis Gallianassa Leach (Figs. 1482, 1483) is known from the Kimmeridgian, as 

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

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

 doubtfully represented in the Eocene of Hungary by chelae referred to the Recent 

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



§ 4. Brachyüra. 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. 



1 The generic name Homarus Milne Edw. is most commonly used for the Lobster, and Astacus 

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

 PotainoUm 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. 



