THE STENID^ AND 0^L\L1'DJE. 83 



Next comes the family of the Stenidae. These insects may 

 be known by the position of the antennae, which are generally 

 set between the eyes or on the front margin of the forehead. 

 The basal joint of the maxillary palpi is long, and the last joint 

 almost imperceptible. See Fig. g on Woodcut IX. 



Sometimes the young entomologist is much puzzled by a 

 phenomenon which takes place with sundry small Beetles 

 belonging to the Brachelytra. As soon as they are killed a 

 long and slender tongue-like organ darts from the mouth, and 

 protrudes itself until it looks like a proboscis. These Beetles 

 belong to the genus Stenus, of which we have an examp-le in 

 Stenus bimacidatus, which is shown on Woodcut IX. Fig. 2. 

 This tongue-like organ is in fact composed of the ligula, the two 

 paraglossse, and the labial palpi, as may be seen by reference to 

 the same illustration. Fig. a. The mandibles of this genus 

 are strongly formed, having one very large tooth, and four 

 very small teeth, as may be seen at Fig. b. The fourth joint 

 of the tarsi has a slightly double lobe. The long and slender 

 maxillary palpus is shown at g. 



The present species is black, with the exception of a roubd 

 ta\viiy spot on each elytron, from which the insect has derived 

 its specific name of birnaculatus, or ' two-spotted.' The surface 

 is thickly and deeply punctured, and is covered with a scanty 

 whitish down. There is a deep furrow along the middle of the 

 thorax. The legs are tawny, with the exception of the knees 

 and tarsi, which are black. 



This is la very common and very good example of the genus, 

 and indeed so well exhibits the characteristics of the family 

 that it is worth a detailed examination. It is a very common 

 insect, being found all over England, and almost always to be 

 taken on the banks of ponds and rivers among the aquatic 

 plants. In tolerably warm weather it may be taken runnino- 

 about upon the stems of the plants, and on cold days lurking 

 in the muddy soil about their roots. Mr. E. A. Smith, to 

 whom I am indebted for much information concerning the 

 smaller Brachelytra, tells me that all the spotted Steni are 

 found in the wettest situations. This genus is a very large one, 

 containing more than fifty species. 



The next family on our list is that of the Omalidse. In 



2 



