10 Mr. David Sharp on the 



Closely allied to our Eiu'opean species, obscurella, grisea, 

 and algarum, but readily distinguished from them by the 

 short basal joint of the posterior tarsi. In size and ap- 

 pearance it greatly resembles a true obscurella, but it has 

 the antennae longer, the anterior parts of the body much 

 more strongly punctured, with less distinct pubescence, 

 and therefore less opaque, and the hind body more sparingly 

 punctured. It is really more allied to A. algarum, but its 

 smaller size, stronger punctuation, and less opaque upper 

 surface, readily distinguish it fr'om that species. 



The male is only to be distinguished from the female by 

 the ventral plate of the penultimate segment of the hind 

 body ; this is just a little more produced and pointed in 

 the middle in the male than it is in the female. 



Under seaweed at Amakusa and Iwosima, near 

 Nagasaki. 



17. Myrmedonia comes, n. sp. (afSnis M. funestce). 

 Nigro-fusca, nitida, antennis pedibusque rufis ; prothorace 

 subquadrato, basin versus leviter angustato, parce punc- 

 tulato, angulis posterioribus minus rotundatis ; elytris 

 prothoracis longitudine sat crebre punctatis; abdomine 

 supra Isevigato. Long. 2\ — 2| lin. 



Mas, a femina vix distinguendus. 



This species is closely allied to our European M.funesta; 

 it greatly resembles it in colour and in the structui-e of its 

 antenna. It is however a little more slender, the thorax 

 and elytra are less closely punctured, its prothorax is 

 longer in proportion to its Avidth, more distinctly narrowed 

 behind, and has its hinder angles less obtuse than fu~ 

 nesta. 



This species, as well as the M. soclus, is found in the 

 nests of Formica japonica, a tree ant allied to the Euro- 

 pean F. puhescens. 



18. M. cognata, Mark. var. ? A single specimen only; 

 about whose sex I am in doubt, and cannot decide whether 

 it be sufficiently distinct from cognata. 



19. Myrmedonia socius, n. sp. (affinis M. fnnestcB). 

 Nigro-fusca, antennis pedibiisque rufis, elytris fuscis; pro- 

 thorace parce punctato, transversim subquadrato, utrinque 

 versus latus oblique impresso ; elytris prothoracis longi- 



