The History of a Long-forgotten British Lithobius. 367 



margin and ending about the middle of the inner margin, a 

 much broken irregular band ; beyond this from the apex to 

 the anal angle a faint greyish line bent inwards on account 

 of a rather large black spot inwardly bordered with orange 

 between the two lower median nervules ; a faint submarginal 

 line and a narrow black marginal line inwardly bordered with 

 pure white. The lobe black, with a few bluish scales and an 

 orange patch above. 



Head white between the eyes ; thorax and abdomen blackish 

 above, with blue scales. Abdomen creamy white below ; legs 

 black, with white spots. Antenna? black, annulated with 

 white. Palpi white, with black tips. 



Expanse 1-1^ inch. 



Hah. Sierra Leone. Mus. Druce. 



Although the collection contains about forty specimens 

 there are no females amongst them. 



The spot between the nervules on underside of hind wing 

 is frequently annulated with orange, and several specimens 

 have a distinct white ringed spot in the cell of fore wing 

 below, but on one wing only. 



XXXIX. — The History of a Long-forgotten British 

 Lithobius. By R. I. Pocock. 



In many, if not most, zoological groups there is an unfortu- 

 nately large category of species which are tacitly ignored by 

 more modern authors and consigned to oblivion by their 

 common consent. For this neglect there is generally ample 

 excuse, the excuse being often traceable to absence of locality 

 for the typical specimen, or more often to some errors or 

 omissions committed by the writer who first described the 

 species. To rescue such a species from its fate is always 

 gratifying, and the task is rendered still more so when it 

 incidentally adds fresh and interesting facts to the history of 

 the species by shedding unexpected light upon its synonymy, 

 distribution, or structural variability. 



Such species are Lithobius pilicornis and L. Sloanei of 

 Newport. The first-named was originally described on p. 96 

 vol. xiii. of this Magazine, but subsequently and more fully on 

 p. 369 of vol. xix. of the Trans. Linn. Soc, this last descrip- 

 tion being repeated in the ' Catalogue of the Myriopoda iu 

 the British Museum.' Immediately following the first 

 description of the species is the description of the second, L. 



