Medun.'] 



STArHYLINID.1:. 



313 



the following remarks :— «' This character appears to me of primary im- 

 portance in tlie classi6cation of the genera hitherto associated under the 

 name of Lithoc/iaris, and to it I would add the structure of the labrum, 

 the width of the neck, the dilatation of the front tarsi, the relative pro- 

 portions of the joints of the hind tarsus, and the structure of the fourth 

 joint of the latter organ ; by so doing a series of very natural genera is 

 obtained, while on the other hand if this be not attended to, it will be 

 found impossible to separate Litliocharis from the genera near Lathro- 

 hium at the one extremity, and those near Sunius at the other." The 

 united genera contain upwards of 150 species from all parts of the world, 

 the great majority of which belong to Medon; there are eleven in- 

 digenous species, some of which are among the rarest of our StaphylinidaB, 

 one or two indeed being unique or almost unique as British ; they occur 

 chiefly at the bottoms of haystacks, in moss, dead leaves, &c. ; several of 

 them _ are very closely allied, and require great care in their deter- 

 mination, the distinctions being chiefly comparative. 



I. Temples almost meeting beneath, or separated by 

 a very narrow interval ; upper surface more or less 

 brown or pitchy, or pitchy black with red elytra. 



{Medon, i. sp.) 

 i. Length 6 mm. ; head oblong; posterior tarsi as 



long as the tibiae 



ii. Length not exceeding 5 mm., usually less ; head 

 subquadrate ; posterior tarsi distinctly shorter 



than tibiae. 

 1. Upper surface black or pitchy black, with 

 elytra bright red ; head coarsely punctured ; 

 thorax with central smooth line distinct . . 



M. CASTANEUS, Orav. 



. Upper surface more or less castaneous or 

 pitchy, sometimes in part ferruginous. 



A. Thorax without apparent central smooth 

 line, evenly punctured throughout .... 



B. Thorax with central smooth line more or 



less distinct. 



a. Head and thorax pitchy black, with a 

 very distinct smooth central line on each . 



b. Head pitchy, thorax and elytra reddish 

 castaneous, with smooth central liuo 

 obsolete on the former and more or less 



distinct on the latter. 



a*. Elytra about as long as thorax, punc- 

 tuation of head distinct and ratlier deep. 



b*. Elytra distinctly longer than thorax; 



punctuation of head confused and finer. 



C. Head black or blackish, extremely finely 



punctured ; form narrower and more 

 slender. 



a*. Thorax broader in proportion to 

 elytra; central smooth line of thorax 

 more or less distinct throughout; apex 

 of mesosternum with a short keel . , 



b*. Thorax narrower in proportion to 



M. POCOFEE, Pei/r. 



(mariiimtcs, Aubc). 



M. DILUTUS, Sr. 



M. PiCEUS, Kr. 



M. BEUNNETTS, Er. 

 M. FUSCULUS, Mann. 



M. EiPicoLA, Kr. 



