766 



ARTHROPODA 



PHYLUM VII 



The Oxyrhyncka have the carapace narrowed in front and produced into a more 

 distinct rostrum. Fossil forms are few and generally rather small. 



A, B, Ilanina marestiana König (=ß. helli Schafli.). Bocene ; Kressenbeig, Bavaria. Ventral and 

 dorsal views. C, Chela of R. bouükana M. Edw. Eocene ; Biarritz, France. 1/2- 



Micromaia Bittner 



Fig. 1489. 



Micromaia tuherculata 

 Bittner. Eocene ; San 

 Giovanni lUarione, Italy. 

 (After Bittner.) 



lateral. Since, however, it 

 they are not separated in 

 the more recent Systems of 

 Classification. 



The Catometopous 

 families -are not well repre- 

 sented among fossils. Litho- 

 phylax Milne Edwards, 

 from the Upper Cretaceous, 

 is an early and somewhat 

 doubtful form. Galenopsis 

 and Coeloma Milne Edwards 

 (Fig. 1490) ; Litoricola 

 Woodward ; and Palaeo- 

 grapsus Bittner, are known 

 from the Eocene and Oligo- 

 ce^e. The Recent Gecar- 



and Microthorax Noetling, are Eocene and 

 Miocene forms respectively. 

 The Recent Lamhrus Leach 

 is known from the Eocene, 

 and Maia Lamarck from 

 the Pliocene. 



The subtribe Brachy- 

 rhyncha includes a large 

 number of families which 

 are often divided into two 

 gronps : ( 1 ) the Cyclome- 

 topa, with the carapace 

 broad and arcuate in 

 front ; and (2) the Gatome- 

 topa, in which the carapace 

 is more or less quadri- 

 impossible to distinguish the two groups sharply. 



Fig. 1490. 



Coeloma vigil M. Edw. Eocene 

 Laverda, Italy. 



Lobocarcinus pauUno vjuertemhergicus v. Meyer. Eocene ' 

 Mokkatam, near Cairo, Egypt. Male. 



