LITERATURE OF CRUSTACEA. 



567 



evidence of the existence of genuine Crabs is not perfectly clear ; 

 since the Palccinachus longipes of the Forest Marble (Lower Oolites), 

 described by Dr Henry Woodward as a Crab, is not completely 

 known, and the Jurassic genus 

 Prosopon may perhaps be refer- 

 able to the Anomura. In the 

 Cretaceous rocks there are various 

 Decapods of the family of the 

 Sponge-crabs, which form a tran- 

 sitional group between the Brachy- 

 ura and Anomura, such as the 

 genus Dromiopsis ; but there are 

 also genuine Crabs, such as Palceo- 

 corystes, Eucorystes, Necrocarcinus, 

 Etyus, and Xantho, representing 

 several of the existing families of 

 the Brachyura. The Eocene de- 

 posits, and particularly those of Britain (the London Clay), have 

 proved very rich in the remains of Brachyurous Decapods, some of 

 the forms of this period belonging to extinct genera (such as Micro- 

 maia, Psammoca?'tinus, Palceocarpilius, fig. 429, Lobocarcinus, Xa?t- 

 thilites, and, above all, Xanthopsis), while others are referable to 

 such existing genera as Cancer and Xantho. The later Tertiary 

 deposits have yielded comparatively few remains of Brachyura, and 

 these of little special interest, but the fresh-water genus Telphusa and 

 the terrestrial genus Gecarcinus are both represented in the Miocene 

 deposits of CEningen. 



Fig. 429 — Pal&ocarpiliiis uiacroclieihis. 

 Eocene. 



LITERATURE OF CRUSTACEA. 



General. 



1. " Gliederfiissler." ' Bronn's Klassenund Ordnungen des Thierreichs,' 



vol. v. Gerstaecker. 1866-89. 



2. Article " Crustacea," in ' Encyclopaedia Britannica,' 9th ed. vol. vi. 



Henry Woodward. 1877. 



3. " Histoire Naturelle des Crustaces." Milne-Edwards. 1834-40. 



4. u Histoire Naturelle des Crustaces fossiles." Brongniart and Des- 



marest. 1822. 



5. " Catalogue of the British Fossil Crustacea." Henry Woodward. 



1877. 



6. " Crustacea of the United States Exploring Expedition." Dana. 



1852-53. 



7. " Handbuch der Pakeontologie." Bd. I., Abth. 2. 1885. Zittel. 



ClRRIPEDIA. 



" Monograph of the Cirripedia." Darwin, 

 didas," 1851. "Balanidae," 1854. 



Ray Society.' " Lepa- 



