6 KOBELT : ON THE LAND SHELLS OF GIBRALTAR. 



in many cases, also spots in various stages of develop- 

 ment. All these specimens have a light yellow ground 

 color without a lighter stripe at the keel. By far the 

 most of them however have, besides a darker yellow 

 tint, a lighter band in the middle, and also dark horn- 

 colored markings. The bands are broken into spots 

 with the exception of the middle one lying above the 

 lighter stripe, which is often well marked. 



H. Coquandi was found almost everywhere along 

 the more cultivated parts of the rock, but only in single 

 specimens. I only collected about 20 of them, all fully 

 developed. It is most abundant between Signal Point 

 and O'Hara Tower, on the road joining these two 

 localities. In June however, I found a great number 

 of young specimens on the steep foot path leading from 

 Mediterranean Road to the ridge of the rock, crawling 

 on Chamcerops humilis its favourite plant. 

 9. Helix (Macularia) lactea var. alybensis m. 



I have already minutely dealt with this form and 

 its relations to the allied South Spanish and North 

 African forms in the Iconographie (Neue Folge, vol. i., 

 and illustrated a specimen from Gibraltar, fig. 67, p. 

 28). It is commonly met with in masses in rock 

 crevices, not unfrequently in company withri^T. itiarmo- 

 rata, also on the under side of Agave leaves. The 

 frequency of albinos is very striking, especially in the 

 higher regions. I gathered in the few days of my 

 sojourn about 30 specimens in all stages of growth, 

 with transparent bands or only with transparent spots, 

 but likewise thick-shelled and completely opaque, and 

 sometimes with white, sometimes with rose-coloured 

 peristome. On the opposite side, near Algesiras, a 

 closely-allied form occurs {H. tigrina Servain), which 

 is somewhat flatter however, and shows a more inflated 

 last whorl. 



J.C., iv., January, 1883 



