STAPIIYLINIDAE. 103 



in some genera the tarsi are 5-jointed, in others 3-jointed. Th(i 

 species are found partly in wet places, partly (Platystethus and 

 certain Oxytelus) in dung and other decomposing material. 

 The genera may be distinguished as follows : — 



Tarsi 3-jointed. 2. 



Tarsi 5-jointed. 9. 



2. TibiiB more or less spinous on outer margin. 3. 

 Tibiae pubescent. 6. 



3. Tibiae with a single row of spines (body depressed). 4. 

 Front tibiae with two rows of spines ; antennae strongly geniculate ; 



(body cylindrical). Bledius. 



4. Front tibiae alone with a single row of spines. 5. 

 Front and middle tibiae with a single row of spines. Platystethus. 



5. Middle coxtu separated. Oxytelus. 

 Middle coxae contiguous. Haploderus. 



6. Scutel visible. 7. 

 Scutel invisible. Trogophlceus. 



7. Head not constricted behind ; body pubescent. s. 

 Head strongly constricted behind ; body glabrous. Apocellus. 



8. Maxillary palpi with last joint conical, acute. Ancyrophorus. 

 Maxillary j^alpi with last joint subulate ; sutural angle of elytra trun- 

 cate, exposing slightly the wings. Thinobius. 



9. Antennae subliliform. 10. 

 Antennae with last three joints abruptly wider. Syntomium. 

 Antennae with last five joints wider ; prothorax toothed at tlie sides ; 



mandibles with a long median tooth. Zalobius. 



10. Middle coxae distant. Coprophilus. 



Middle coxae contiguous. Deleaster. 



DistemmuH Lee., formerly included in this group, is really 

 only a species of Horaalium, and identical with the European 

 H. lapjMmicum. 



Tribe VIII.— HOMALIXI. 



In this tribe the prothoracic spiracles are concealed by the 

 iuflexed portion of the pronotum ; the presternum behind the 

 coxae is membranous ; the anterior coxae are conical and promi- 

 nent, the posterior ones transverse; the hind trochanters are on 

 the internal margin of the thighs; the tarsi are 5-jointed; the 

 palpi are filiform, except in a few genera, where they are subulate; 

 the head is furnished Ixdiind with two simple lenses or ocelli, 

 which are usually ])laced on a line joining the posterior margins 

 of the eyes. The aiiteniiie are inserted under the lateral margins 

 of the front. The second ventral segment is carinate at the base. 



