Cii PROCEEDINGS OE THE GEOLOGICAL SOCIETY. [May 1 896, 



length and stoutness. The abdominal segments are short and fiat, 

 hut narrower than the carapace, and terminate in a rather pointed 

 telson and 4 tail-laminse. The first pair of thoracic legs are nearly 

 as long as the body : all the limbs have chelate extremities, save the 

 last pair, the extremities of which are simple. 



It is not improbable that the earliest members of this ancient 

 family (which attained its majority in the Upper Jurassic period) 

 may be traced back as far as the Lower Carboniferous of Eskdale, 

 Scotland ; and they may be identified with such species as Anthra- 

 palcemon Macconochii, A. Woodwardii, and some others (see Quart. 

 Journ. Geol. Soc. 1879, vol. xxxv. pi. xxiii. p. 464) described by 

 11. Etheridge, Jun. Another early form is the Eryon raiblanus, 

 Bronn, sp., from the Trias of Raibl, Bohemia; followed by the 

 Eryon (Tropifer) Icevis of Gould from the Rhsetic Bone-bed of 

 Aust. 



In the Lias formation there are ten described species, namely : — - 



Eryon Calvadosii, Moriere, TJ. Lias, Caine, Calvados. 



„ Hartmanni, Meyer, TJ. Lias, Wurtemberg. 



„ Edwardsi, Moriere, U. Lias, Calvados. 



„ Moorei, H. Woodw., U. Lias, Ilminster. 



„ Escheri, Oppel, L. Lias, Baden. 



„ antiquus, Brodp., L. Lias, Lyme Regis. 



„ barrovensis, M'Coy, L. Lias, Barrow-on-Soar. 



„ wilmcotensis, H. Woodw., L. Lias, Wilmcote. 



„ Brodiei, H. Woodw., L. Lia9, Lyme Regis. 



„ crassickelis, H. Woodw., L. Lias, Lyme Regis. 



One species occurs in the Great Oolite (Stonesfield Slate), namely, 

 the Eryon Stoddarti of H. Woodward, while the Eryon Perroni of 

 Etallon occurs in the Oxford Clay of Calmoutiers, Haute Saone, 

 France. 



Ten species of Eryon have been described from the Lithographic 

 Stone of Solenhofen (probably near the horizon of the Kimmeridge 

 Clay of England), namely : — 



Eryon propinquus, Schloth. 

 „ spinimanus, Germar. 

 „ orbiculatus, Miinst. 

 „ elongatus, Miinst. 

 „ arctiformis, Schloth. 



Eryon bilobatiis, Miinst. 

 „ longipes, Fraas. 

 „ Schuberti, Meyer. 

 „ Redtenbacheri, Miinst. 

 „ Oppeli, H. Woodw. 



I have described one Lower Cretaceous species under the name 

 of Eryon neocomiensis, from the Neocomian of Silesia. 



Lastly, we are indebted to the Naturalists of the Challenger 

 Expedition for a knowledge of several living representatives of 



