COLEOPTERA. 387 



an arcuated brown horn. Its external tissue is a gummy paste, which, 

 though fluid at first, subsequently hardens, and becomes impervious to 

 water. The ova it contains are arranged symmetrically, and kept in situ 

 by a sort of white down. These cocoons float on the water. 



The larva is depressed, blackish and rugose, and has the faculty of throw- 

 ing back its brown, smooth, round head. This enables it to capture the 

 little Mollusca which navigate the surface of the water, its back serving as 

 a point d'appui or anvil on which it mashes the shell in order to devour the 

 animal it contains. The body of these larvae becomes flabby as soon as they 

 are caught. They swim with great facility, and are provided with two 

 fleshy appendages which serve to maintain them on the surface of the water, 

 head downwards, when they come there to respire. According to M. Miger, 

 the larvae of other Hydrophilii are deprived of these appendages, and neither 

 swim nor suspend themselves like those of which we have been speaking. 

 The females of these species swim with difficulty, and carry their ova under 

 the abdomen enclosed in a silken web. 



There are many other genera of Hydrophilians, such as Hydrochus, Odhe- 

 bius, Spercheus, Sec., differing in form, the arrangement of the antennae, &c. 



Our second tribe, or the SPH^ERIDIOTA, consists of terrestrial 

 Palpicornes, with tarsi composed of five very distinct joints, the first 

 of which is at least as long as the second. The maxillary palpi are 

 somewhat shorter than the antennae, with the third joint longer, in- 

 flated, and in the form of a reversed cone. The maxillary lobes are 

 membranous. 



The body is nearly hemispherical, the posterior extremity of the 

 prsesternum is prolonged into a point, and the tibice are spinous; 

 those that are anterior are palmated or digitated in the large spe- 

 cies. The antenna always consist of nine joints, or of eight, if the 

 last be considered as an appendage of the penultimate. 



These Insects are small, and inhabit cow-dung and other matters; 

 certain species are found near the shores of rivers, &c. They 

 compose the genus 



SPHJERIDIUM, Fab. 



From which, however, we must separate several species, a division already 

 effected by Olivier. Dr Leach only considers as such those in which the 

 anterior tarsi of the males are dilated. Such is 



S. 4-maculatum. It is of a shining black and smooth; the scutellum is 

 elongated, and the legs are very spinous? a blood-red spot at the base of 

 each elytron, and their extremity reddish In some individuals these spots 

 diminish or disappear. 





