18981 



DIAPELTIS, A FOSSIL INSECT 



43 



blattid larva in the Geological Magazine for 1887 (docade iii. vol. iv., 

 p. 433, pi. xii., fig. 1). In the figure of that fossil larva two spots 

 are shown near the middle of the pronotum ; and on looking through 

 a series of existing Blattidae many species may be found in which 

 either two spots, two pits, or two tubercles occur in a similar position. 

 Four pits may sometimes be seen, though I have not met with any 

 species in which one pair is placed close to the anterior margin. 



But, after all, why should so much importance be attached to 

 these eyes of Dipeltis, seeing that no trace of them appears in the 

 figure of the second species. 



Fig. 1. 



Fig, 2. 



Outline figure of Carboniferous Dipeltis (1) compared witli Photograph of Recent Larva 

 of a Beetle (2), natural size. 



So far, therefore, as Mr Bernard's objection is concerned, I think 

 the claims of Dipeltis to be considered as an insect are fairly well 

 established. And if an insect, the next question is what sort of an 

 insect ? 



At first sight the figures of Dipeltis reminded me most of a 

 remarkable coleopterous larva, a photograph of which I am enabled, 

 through the kindness of my colleague, Mr Gepp, to offer for compari- 

 son (fig. 2). Nothing definite is yet known of the life history of this 

 larva. A somewhat similar larva was figured by Westwood in his 

 " Introduction to the Classification of Insects," and was considered 

 by him to belong to the malacoderm series, and to the family Lycidae. 

 In dead specimens the head is always retracted, and concealed, within 

 the cavity of the prothorax. 



That Dipeltis was not, however, the larva of a beetle may be in- 

 ferred from the presence of the long segmented cerci in one of the 

 species, though this fact in itself affords no absolute proof. Creatures 

 of the cockroach kind were fairly abundant in Carboniferous times, 



