216 



PTINID.E. 



rality of the Sphcerici, it varies immensely in stature (according to 

 the circumstances under which it is found) the examples from the 

 northern Deserta descending to a most diminutive size. It occurs in 

 many different situations, but is extremely partial to the pithy stems 

 of Thistles (especially the gigantic Silylum Marianum, Grtn., the 

 Holy Thistle of the ancients). However, it is often to be met with, 

 in absolute profusion, harbouring amongst lichen within the crevices 

 of the weather-beaten peaks ; as well as amongst the dead leaves 

 around the roots of Semperviva, the flat rosettes of which are fre- 

 quently so conspicuous on the faces of the perpendicular rocks. 





612. Sphaericus simplex. 



Sphaericus simplex, WolL, Tr.Ent. Soc. Land. i. 207. pi. viii. f. 6 (1862). 

 , Id, Cat. Can. Col. 241 (1864). 



Habitat Canarienses (Gom., Hierro), in locis similibus ac praecedens. 



Although at first sight so closely resembling the dlbopietus of the 

 Madeiran Group that it might well be mistaken for it, I nevertheless 

 believe that the present Sphcericus must not be regarded as any local 

 modification of that insect. And yet, on the other hand, its distinc- 

 tions are so little apparent until the specimens are examined with 

 the greatest care, that it is difficult to feel altogether satisfied that such 

 may not be the case. At any rate since I have already recorded the 

 T. simplex as a separate species, and t since one at least of its small 

 diagnostic features is structural, I will not suppress it ; though, in 

 that case, it must certainly be looked upon as at all events the Cana- 

 rian representative of its Madeiran ally. 



I have taken the S. simplex in Hierro, and it was found by the 

 Messrs. Crotch both in that island and Gomera*. 



613. Sphsericus pilula. 



Ptinus pilula, WoU., Ins. Mad. 266 (1854). 

 , Id., Cat. Mad. Col. 90 (1857). 



Habitat Maderenses (Mad.), semel tantum reperttis. 



* The S. simplex differs from the albopictus in its prothorax (when denuded 

 of its scales) being a little less densely, and less regularly, scabrous (having more 

 the appearance of being roughly punctured), as also somewhat more evidently 

 margined along its basal edge ; in its elytra being usually rather rounder, as well 

 as more deeply and sparingly punctured ; and in the penultimate joint of its feet 

 being rather less expanded, and almost simple though this last character is not 

 very evident until the two species are viewed, side by side, beneath the micro- 

 scope. 



