364 Mr. J. J. Walker's notes on Lepidoptera 



duration to Malaga in April and May, 1888. The 

 weather on each occasion was not very favourable, and 

 not much available collecting-ground was to be found ; 

 the country west of the town being a flat, alluvial, highly- 

 cultivated plain for the most part, while on the east side 

 the slopes of the rugged limestone hills are almost 

 entirely occupied by vineyards. A considerable number 

 of species of insects was, however, obtained, including 

 several that were either very rare in, or absent from, the 

 Gibraltar district, EucJiloe tagis, var. hcllezina, E., and 

 Pararge mcera, L., being observed here only. 



Passing next to the African side of the Straits, almost 

 exactly opposite " Mons Calpe " at a distance of 13 miles, 

 the second Pillar of Hercules, " Mons Abyla," the modern 

 Djebel Mousa, or " Ape's Hill," rises as a huge rugged 

 dome-shaped mass of limestone (not distinguishable, in 

 hand specimens, from that of Gibraltar) to a height of 

 2808 ft. I had the good fortune to be enabled to ascend 

 this mountain, from Almanza Bay, on November 4th, 

 1888, a gloriously clear day, when the view from the 

 summit was one never to be forgotten. The ' Grappler' 

 visited on several occasions a little indentation of the 

 coast called Benzus Bay, about five miles west of Ceuta, 

 and at the foot of the main mass of the mountain : here 

 a rugged and stony, but fertile valley, watered by 

 perennial springs in the limestone, is cultivated by an 

 industrious and peaceable community of Moors, who 

 obtain two and sometimes three crops of wheat, maize, 

 and " dhourra " (Holcus sorghum, L.) in the year. A 

 number of interesting insects, not observed at all on the 

 European side, occur at this place. Indeed, the diffe- 

 rence between the faunas on the two shores, when the 

 narrowness of the channel separating them and the 

 comparatively recent date which geologists agree in 

 assigning to its formation are taken into account, 

 appears worthy of special attention. The great depth of 

 the Straits (503 fathoms between Gibraltar and Benzus), 

 and the constant strong current from the Atlantic into 

 the Mediterranean, no doubt render them a much more 

 formidable barrier to the passage of living creatures 

 from side to side than would appear at first sight. 

 Although one of the great migration routes of birds 

 actually crosses this narrow sea, there are several species 

 which come right up to its southern shore, and proceed 



