MIOCENE FAUNA. 



two species of crabs, belonging to two genera. One of them is 

 probably to be referred to Telphusa, the other to Gecarcinus. 

 In the former (fig. 207) the carapace is but slightly rounded at 

 the sides, and its back is covered with small tubercles arranged 

 in rows; whilst in the latter (fig. 208) the carapace is heart- 

 shaped and very much narrowed behind. Its upper surface is 

 closely punctate. In both the (Eningian species the two chelse 

 are of equal strength, and the legs are furnished with a knife - 

 like pointed terminal joint ; the third pair of legs are somewhat 

 longer than the rest. The (Eningian river- crab (Telphusa 

 speciosa, Myr.)* resembles the southern European species, the 

 only crab which inhabits rivers and lakes in Europe, and which 

 appears to be distributed in all Mediterranean countries. It is 

 captured in great numbers in the Lake of Albano, and eaten in 

 Rome during Lent by all classes of people. Even in ancient 

 times it must have been of importance, since it appears on old 

 coins of Agrigentum in Sicily. There is nothing remarkable 

 therefore in the occurrence of this genus at GEningen, as it is 

 one of those Mediterranean types which were at that time nume- 

 rously represented in Switzerland, and lived in freshwater. 



The Land-Crabs (Gecarcinus) are quite foreign to the European 

 fauna. They occur at present only in tropical America, especi- 

 ally in the West Indies, where they are known under the name 

 of " Tulurlu.-" They live in the forests in the interior of the 

 country, and form burrows in the ground, which they quit only 

 at night in order to seek for prey. Once in the year they unite 



* M. de Meyer described this species as Grapsus speniosus (Palaeontogra- 

 phica, x. p. 168, 1863); and it certainly belongs to the group of the "Brachy- 

 ures quadrilate rales " of Latreille, which includes the Grapsi and the Land- 

 and River-Crabs. But of these it seems to Professor Heer that Telphusa is 

 the genus in which it must be ranged. The form of the carapace, which 

 is more narrowed behind and not toothed at the margin, and the com- 

 parative lengths and form of the legs, seem to contradict its reference to 

 Grapsus. In that genus the second pair of legs (the first from the chelae) are 

 much shorter than all the rest, which also have broader and stronger femora. 

 In all these characters the (Eningian crab agrees with Telphusa, as well as in 

 the form of the outer inaxillipeds. That the chelae are unarmed, and the 

 legs not set with stiff bristles, are important specific characters. Fig. 207 

 represents a small specimen ; the species occurs twice of this size. The tail 

 in the female is much broader than in the male. 



