PROOFS, ILLUSTRATIONS, AUTHORITIES, ETC. XV 



formations. These cirripedes now abound so under every zone, all 

 over the world, that the present period will hereafter apparently have 

 as good a claim to be called the Age of Cirripedes, as the Palaeozoic 

 period has to be called the Age of Trilobites." Charles Darwin : 

 Monograph of Fossil Lepadidoe, 1851. 



Arachnida and Insecta. Two species of Coleoptera and some 

 Arachnida, particularly a scorpion, have been found in the Carboni- 

 ferous formation ; also a neuropterous insect resembling a Cordalio 

 and another of the same order related to the Phasmidas. 



One shale bed in the Lias (Gloucestershire) is charged with wing- 

 cases of coleoptera along with some nearly entire beetles, of which the 

 eyes are preserved. " Throughout an extensive district, several bands 

 of this lias have been termed Insect Limestone, in consequence of the 

 great number of such fossils, no less than 300 specimens of hexapods 

 having been obtained, comprising both wood-eating and herb-devour- 

 ing beetles of the Linnsean genera, Carabas, Elater, and others, 

 besides Grasshoppers [Hemiptera], and detached wings of Dragon- 

 flies and May-flies, or insects referable to the Linnsean genera Libel- 

 lula, Ephemera, Hemerobius, and Panorpa [Neuroptera], the whole 

 assemblage being no less than twenty-four families." Lyell, 1851. 



Professor Heer thinks it probable " that lepidopterous insects were 

 first created in the tertiary period, because the only well determined 

 specimens of that order yet known to paleontologists have come from 

 tertiary strata." Id. 



Our fossil insects are too few to allow of our bringing them forward 

 with any confidence; but it is meanwhile remarkable that they are 

 first seen so long after the Crustacea, to which the} T are superior in 

 organization, and that even amongst themselves the lowest families 

 appear first. 



That insects are above Crustacea is affirmed by Professor Agassiz. 

 " In every respect," says he, " insects, considered as a whole class, are 

 more highly organized [than Crustacea], their higher types assuming 

 a division of the body into three distinct regions, undergoing also 

 far more extensive metamorphosis, and assuming finally an aerial 

 mode of respiration, to which the Crustacea do not reach." Silli- 

 tnans American Journal, &{c., 1850. 



Agassiz classes Arachnida and Myriapoda with true insects, con- 

 sidering them as only lower degrees of development " the Myriapoda 

 representing in a permanent state of development, and with the 

 structure of true insects, the form of their caterpillars ; the spiders, 

 with their cephalic and thoracic regions united into a cephalo-thorax, 

 representing their chiysalis in a permanent state of development." In 

 consideration of these embryonic particulars, he deems Myriapoda as 

 the lowest type, the Arachnida next, and the true insects highest, the 

 sucking tribes being amongst these last the most elevated. 



"If we now," he says, " consider the insects proper, we shall find 

 here again a strict accordance with the results we have already 

 derived from the investigation of the lower classes, namely, that tiie 



