HETEROMERA 265 



Fam. 65. Othniidae. — Onlyabout ten species are known of this 

 dubious family. Tliey are small Insects with weak integument, 

 and are said by Leconte and Horn to be distinguished from 

 " degraded Tenebrionidae " by the more mobile abdominal seg- 

 ments, the hind-margins of which are semi-membranous. The 

 antennae are of the clubbed shape, characteristic of " Clavicornia," 

 but this also occurs in numerous undoubted Tenebrionidae. 

 Species of Othnius have been found in Japan and Borneo, as 

 well as in North America. Xothing is known as to their 

 metamorphoses. 



Fam. 66. .^gialitidae. — All the coxae very ividely separated ; 

 no eo-adaptation betioeen the sides of the abdomen and the edges of 

 the loing-cases ; five ventral segments a.nd tip of a sixth visible. 

 Two minute and rare Insects from JSTorth-West America constitute 

 this family. It is distinguished from Pythidae by the minute 

 front coxae, widely separated, completely closed in, and deeply 

 embedded in the prosternum. 



Fam. 67. Monommidae. — This is a small family of less than 

 100 species, the members of which have the details of their 

 external structure much modified, permitting the Insect to pack 

 itself up in repose in a very perfect manner. They are of small 

 size and oval form ; and are absent from Europe and the Anti- 

 podes. Nothing appears to be known as to the metamorphosis. 



Fam. 68. Nilionidae. — Broad, eireular Heteromera, of moderate 

 size, with the front coxae but little separated, and the anterior 

 acetabula closed, though having the appearaiice of being open in 

 consequence of the tips of the ephnera being free. The inflexed 

 portion of the wijig-cases remarkably broad. A small family of 

 less than fifty species, found on fungi, chiefiy in South America. 

 The - metamorphoses are not known. It is of very doubtful 

 validity. 



Fam. 69. Melandryidae. — Head not constricted behind the 

 eyes ; anterior acetabula not closed ; claws smooth. Prothorax broad 

 behind. These are loosely -fitted-together Insects, of moderate 

 or small size, frequenting dry wood or fungi. About 200 species 

 are known, found chiefly in temperate regions. The few described 

 larvae are rather varied in their details and cannot be generalised 

 at present. The characters of the members of this family require 

 fresh investigation. 



Fam. 70. Pythidae. — Distinguished from Melandryidae by the 



