192 BRITISH SPECIES OP PHALANGIDEA OR HARVEST MEN. 



denticulae were also stronger. Although the usual absence of the 

 two small but prominent teeth 'between the fore margin of the 

 caput and the base of the falces will generally prevent this species 

 being mistaken for Plialangium opilio, yet too much stress must 

 not be laid upon this, as I have an undoubted adult male of 

 0. morio from Scotland, in which two small adjacent projecting 

 pointed tubercles each terminating with a minute black spine, are 

 plainly visible in the centre of the corresponding space where they 

 are found in P. opilio. 



Other characters, however, both of colour, markings, and 

 armature, and the difference also of habitat are quite sufficient for 

 the discrimination of. the two species. 



OLIGOLOPHUS ALPINUS. 



Opilio alpinus Herbst (1799). 



Oligoloplius alpinus Herbst-Simon (1879). 

 PL D, fig. 18. 



This species is so nearly allied to the foregoing 0. morio, that 

 it seems questionable to me whether it be really distinct or not. It 

 resembles it in size, colours, and markings, and most other characters. 

 Mons. Simon says that the males are readily distinguishable by the 

 following characters : " The metatarsi of the third pair of legs are 

 slightly curved, thicker, attenuated at the two extremities, and 

 the tibiae of the first pair have a series of spines (spicules) 

 beneath them, which are always wanting in 0. morio." I submitted 

 several years since examples from * Scotland, Isle of Arran, &c., 

 to M. Simon ; some of these he has determined to be 0. mono 

 and others 0. alpinus. With regard to his first distinguishing 

 character, I can find no difference between those thus determined ; 

 and, as respects the second distinction, the spicules on the inferior side 

 of the tibiae of the first pair of legs are equally numerous and strong 

 in all of them, while there are certainly some, though few and not 

 so strong, beneath the first tibiae of undoubted examples of 



* Kindly collected for me by my cousin, the late Colonel Pickard, 

 R.A., V.C., &c., at Balmoral, and Mr. H. C. Young, late of Glasgow. 



