Mr. Westwood on new Insects. 203 



Rays {Rata) and Eels {Murcena), or are of such a formidable 

 character as to render any security against the injuries of 

 their class unnecessary ; such are the Squalidie or Sharks, 

 which may be said to be predominant among the fishes of 

 the ocean, and the Silin'idce, which maintain a corresponding 

 place in freshwater lakes and rivers. Notwithstanding this 

 diversity, M. Agassiz has turned the external covering of 

 fishes to a happy account in the study of fossil species, of 

 which the scales alone are often the only vestiges that remain; 

 thus a knowledge of eight hundred extinct species has been 

 attained that could not have been characterized by ordinary 

 means. Although the researches of M. Agassiz have added 

 largely to the science of zoology, they have done still more if 

 possible for geology, by "introducing a new element" into 

 our calculations*; no one however is more aware than M. 

 Agassiz himself, of the error into which some are led in sup- 

 posing the lepidermal system to be based on principles that 

 are in any way at variance with the natural classification of 

 animals. By that system M. Agassiz has extended our know- 

 ledge of the natural characters of species, and introduced to 

 the calculations of the zoologist as well as geologist a new 

 element by which Ave must be guided in the study of fossil 

 fishes, rather than a principle opposed to the classification of 

 these or other animals according to their structure and habits. 



XXV. — Insectorum novorum Centuria, auctore 

 J. O. Westwood, F.L.S., &c. 



Decadis secundce, ex ordine CoIeoj)terorwn, Si/nojisis. 



1. CiciNDELA cupreola, W. C. ni*ro-cuprea, purpurascenti tincta, 



sericans, capite magno, inter oculos striatulo ; prothorace sub- 

 cylindrico lateribus vix rotundatis, antice et postice parum con- 

 stricto, elytris concoloribus immaculatis subvariolosis, punctis 

 nonnuUis majoribus aureis, lateribus nitidis, lineaque obliqua 

 mediana in singulo quasi elevata et magis cuprea ; pedibus 

 fuscis, femoribus articuloque 1™° antennarum luteis, labro ^ 

 inermi, $ tridenticulato. Long. corp. lin. 4. Habitat in insula 

 Mauritii, D. Desjardin. IVIus. Westw. 



2. CiciNDELA {Megcdomma, W. S. g. nov. Caput maximum, oculis 



valde prominentibus. Labrum magnum, antice integrum. Man- 

 dibulcC dentibus duobus inter apicem et dentem magnum basa- 

 lem. Palpi labiales articulo penultimo valdfe inflate. Antennae 

 et pedes longissimi. Prothorax capite multo angustior subglo- 

 bosus, antice et postice constrictus. Elytra subbrevia. Tarsi 



* Dr. Buckland's Bridgewatcr Treatise, p. 270. 



