30 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [IS T OY. 20, 



were in a hard quartzite matrix (like the sarsen stones) and almost 

 incapable of development, on account of the intense toughness of the 

 matrix. 



The present examples are from a fine sandy loamy bed, which 

 allows of the fossils being readily extracted ; but they are usually 

 in a most friable state, and constantly give way, owing to their im- 

 perfect fossilization and to cavities in their interior not filled up 

 solid by the matrix. The specimen here described (from Mr. Caleb 

 Evans's collection) is in this crumbling state, and I have had great 

 anxiety on account of its unsafe condition. 



It is to be hoped that others may be found of this new and 

 interesting type. 



LlTORICOLA DENTATA, H. Woodw. PI. II. figS. 2-5. 



This species is considerably smaller than the preceding one ; like 

 it the surface of the carapace is smooth and destitute of those strongly 

 marked divisions which characterize many forms among tbe Portu- 

 nidae and Canceridse. The relative proportions of the carapace are 

 about the same. 



Anterior border 8 lines ; posterior border 5 lines ; greatest breadth 

 (at the angle formed by the two lateral or epibrancbial spines) 12 

 lines ; greatest length 8 bines. Each branchial border is armed with 

 a single small spine just behind the epibranchial spine which marks 

 the greatest breadth of the carapace. 



The hepatic margin is marked by three nearly equal spines, the 

 anterior one being confluent with that forming the orbital border. 



The orbits measure 2 lines in breadth ; the margin appears to be 

 straight ; the frontal or rostral border projects and forms the inner 

 boundary to the orbits, it is 3 lines in breadth, and is deeply furrowed 

 down the centre, which is bent downwards (as in the preceding 

 species), and appears to be blunt in front, with a slightly raised 

 border. The regions of the carapace differ but slightly from those of 

 L. glabra, save that the cardiac region is more expanded posteriorly, 

 and less broad in front. 



The hands are unequal in size, as in the preceding species. The 

 four pairs of running-feet are flattened laterally, and well suited 

 for rapid locomotion on land. 



Only two specimens of this crab, displaying the dorsal aspect, are 

 preserved : the other two examples exhibit the ventral aspect ; but, 

 save for the limbs, they do not offer any clear evidence of the abdomen 

 or the plastrosternal plates or maxillipeds. 



The specimens of L. dentata are all from the cabinet of Mr. C. J. A. 

 Meyer, F.G.S. 



EXPLANATION OF PLATES. 

 Plate I. 



Figs. 1-6. Ehachiosoma bisjnnosa, H. WoodV. 



Fig. 1. Outline figure, natural size, of largest specimen in Mr. Meyer's col- 

 lection, restored from the details furnished by other examples of the 

 same species. . 



