﻿Catalogue of British Fossil Crustacea, 415 



described, and in Bohemia 350 species Jiave been named and 

 figured by Barrande alone. The great Paradoxides Davidis 

 measures nearly two feet in length. As this group ascends in time, 

 we find those extravagantly ornamented and spinose forms, such as 

 Paradoxides and Acidaspis, disappear; and only three genera sur- 

 vive in the Carboniferous, small in size, and very regular and neat 

 in form, especially the genus Griffithides. 



Amphipoda. — The Amphipoda has one representative in the Upper 

 Silurian (the Necrogammarus Salweyi, H. Woodw.) ; it is represented 

 by Gampsonyx in the Coal of Ehenish Prussia ; and by the genus 

 Prosoponiscus in the Permian of Durham. Other (Secondary) species 

 occur in Bavaria, etc. The living genera of Amphipoda are 

 abundant both in marine and freshwater, and some species are even 

 terrestrial in their habits. 



XiPHOSUBA. — The earliest representative of the King-Crabs known 

 is the Neolimulus falcatus, H. Woodw., from the Upper Silurian of 

 Lanarkshire ; several species are met with in the Coal-measures, and 

 are very widely distributed. The genus is represented largely in 

 the Oolite of Bavaria, and is also found living to-day in both the Old 

 and New World. 



EuRTPTERiDA. — The EuRTPTERiDA, like the Trilobita, are an 

 extinct order. They were represented in Devonian and Silurian 

 times by genera, which attained a length of from 5 to 6 feet. They 

 are nearly related to the King-Crabs in structure, but differed in 

 their development as do the Lobsters from the Ci-abs at the present 

 day : the Xiphosura representing the Brachyura, and the Eury- 

 PTERiDA the Macrura. 



Phyllopoda. — The Phyllopoda are represented from the Middle 

 Cambrian to the Tertiary period by many genera. Large extinct 

 forms, closely resembling the little modern Nebalia hipes, were 

 abundant in the Upper Silurian of Ludlow and Lanark. They are 

 represented to-day by species in freshwater, brackish water, salt 

 water, and highly saline salterns and lakes. 



OsTRACODA. — The Bivalved Entomostraca included in this order 

 are largely represented throughout the entire series of stratified 

 rocks, from the Lower Cambrian to the present day; they are equally 

 well represented in a recent state. They not unfrequently (as in 

 the Cypris shales of the Wealden) make up entire strata with their 

 accumialated bivalved carapaces. 



CiRRiPEDiA. (a.) Balanid^. — The oldest fossil sessile Cirripede 

 is the Pyrgoma cretacea, H. Woodw., from the Upper Chalk of 

 Norwich. 



(b.) Lepadid^. — The oldest known pedunculated Cirripede is the 

 Turrilepas Wrightii, H. Woodw., from the Upper Silurian of Dudley. 

 None have been met with lower than the Lias except Turrilepas ; 

 but from the Lias upwards, pedunculated forms are well represented. 



The group is abundant and cosmopolitan in all the seas of the 

 world, parasitic on all objects, living and dead. 



The subjoined Table gives the number of genera, species, and 

 varieties belonging to each order, and suborder in the class Crustacea. 



