17G STAPHYLiNiDiE. [Olignia. 



The three concluding genera of the Aleocharinse, Mylluina, Gymnusa, 

 and Beinojms, have many important points in common ; ahliougli, there- 

 fore, tliey are widely separated by the tarsal system, yet it is certainly 

 the best course to regard them as somewhat exceptional, and to place them 

 together at the end of the gi'oup ; they form the " Deuxieme branche " of 

 Mulsant and Key's family Aleochariens, the " Gymnusaires," the first 

 branch being the " Dinardaires;" they are chiefly characterized by their 

 fusiform shape, setiform labial palpi, and the fact that the hind body is 

 terminated by two more or less prominent styles ; in Myllcena the anterior 

 and intermediate tarsi are four-jointed and the posterior five-jointed, in 

 Gymnusa all the tarsi are five-jointed, while in Deinopsis, which, accord- 

 ing to the tarsal system, forms a separate tribe, they are all three-jointed. 



IVIVZiZiSINA, Erichson. 



About thirty species are at present contained in this genus ; these are 

 very widely distributed, occurring in Europe, North, Central, and South 

 America, Ceylon, Cape Verd Islands, and even in the Sandwich Islands ; 

 as Dr. Sharp observes, the habits of these creatures, which run swiftly in 

 muddy places or live amongst damp moss, render it certain that they are 

 not artificially distributed : the species are exceedingly difficult to distin- 

 guish, as they very closely resemble one another, and there are no striking 

 sexual or structural differences; it is only by comparison that many of 

 them can be separated, and it is therefore obvious that it is useless to 

 attempt to tabulate them satisfactorily ; the first examples of the genus 

 found in Britain were taken bv the Rev. A. Matthews in 1834, who was 

 struck by finding on a piece of bark removed from a willow tree growing 

 at the edge of the water near Weston-on-the-Green, Oxfordshire, " a 

 multitude of small Brachelytrous insects, in a dormant state, each of which 

 held its abdomen raised perpendicularly from its body, without at any 

 time altering its position ;" the labial spines then attracted his attention 

 to the genus, and he discovered five more species which were described 

 by his father (Entomological Magazine, Jan. 1838) under the generic 

 name Centroglossa ; Erichson, however, had a little before named the 

 genus Myllwna ; quite recently Mr. Matthews has published an exhaustive 

 essay on the British species (Cistula Entomologica, Sept. 1883, Part 

 xxvii.), which he brings up to twelve in number, so that all the European 

 species hitherto known are found in Britain ; as Mr. Matthews is our 

 recognized authority on the group, I have followed his essay in the 

 descriptions following: the differences between the species are in most cases 

 comparative ; I have therefore not given any tables. 



The genus Myllccna is chiefly remarkable for the long slender setiform 

 labial palpi, which are indistinctly two-jointed, the very short anterior 

 tarsi, and the hind body strongly narrowed behind, which gives the 

 species the appearance of belonging to the Tachyporinae ; the anterior 

 and intermediate tarsi are four-jointed, and the posterior five-jointed : 



