KOBELT : ON THE LAND SHELLS OF GIBRALTAR. 7 



10. Helix (Macularia) marmorata Femssac. 



This is the characteristic shell of Gibraltar, common 

 in every part of the rock, but easily overlooked, being 

 always concealed in the fissures of rocks, in these 

 however they occasionally stick together in big lumps. 

 I collected the finest specimens towards the Southern 

 Slope. Now and then spotless forms with well marked 

 bands may be found, while usually only the two lowest 

 bands are distinct. Specimens without well marked 

 stripes are less common. There are only two albinos 

 among the several hundred specimens I collected. 



H, marmofata is characteristic of the whole district 

 from Malaga and Grenada to Gibraltar. Helix loxana 

 Rossm. and Helix Pm^tschi Bourg. {balearica var, pid- 

 chella Rossm.) are allied to it by transitions. I presume 

 it may also be found beyond the Straits at the Monkey 

 Mount. 



11. Helix (Iberus?) Scherzeri Zelebor. 



This interesting shell, after having been almost 

 unknown for a long time, was rediscovered, and I have 

 already made a full report in the " Jahrbuch," 1881, as 

 well as in the "Iconographie" (Neue Folge, i., p. 24, 

 fig. 64), and figured the various forms. The reason 

 for its having been overlooked is that it only lives on 

 the loftiest parts, and there only in rock crevices diffi- 

 cult of access. In these however it occurs in large 

 heaps cemented together by a blackish mucus, even 

 the dead ones are frequently still clinging to the others. 

 I found them at the Rock Gun as well as at Signal 

 Point and below O'Hara Tower, but always confined 

 to a few fissures, which nevertheless yield several 

 hundred specimens. It is easily distinguishable from 

 H. marmorata by the white peristome, and stands 

 between the latter and the splendid forms I discovered 

 in the mountains near Tetuan, and which are closely 



