I lO 
The Iruh Naturalist. 
April, 
Helicella zakarensis in Co. Down. 
Some 3'ears ago, while staying at Rostrevor, I collected some land 
mollusca in the ruins of a cottage about a mile from that place, on the 
road to Rathfryland 7na Mayobridge. The majority were H. rufescens, 
but among these was a shell which, at the time, I thought was a speci- 
men of H. pistma, and knowing that this species was found on the Louth 
and Meath coasts, it seemed to me more than probable that it had come 
from there. It did not happen to attract my attention again until about 
a year ago, when I came across it, and noticed that it was much flatter 
than H. pisana, finely striated, and had a very wide umbilicus, more 
like that of H. itala {ericetoruvi). In colour it was pale brown, with 
darker blotches of the same, in that respect somewhat like var. ornata 
of H. virgata. The striations were its most distinguishing characteristic, 
being very regular and fine. The specimen was alive, but not full 
grown, being about 15mm. in diameter, and having five whorls, whereas 
a H. pisana of the same measurement has only four whorls. None of 
the other xerophile species which are common on many parts of the 
Irish coast are found at Rostrevor, though two of them have been 
found lately at Cranfield Point, about ten miles further south. Not 
being able to name the shell myself, I passed it on to Mr. Welch, and 
he forwarded it to several experts, finally sending it to Messrs. 
Kennard and B. B, Woodward, of London, who compared it with 
specimens in the Norman collection at the British Museum, and came 
to the conclusion that it was a young specimen of Helicella zakarensis 
Kobelt. The following is an extract from a letter of Mr. A. S. Kennard's 
to Mr. Welch : — " We at once rejected H. virgata as clean out of it. It 
was a young shell, perhaps two-thirds grown, so it could not be that 
species, and when we got a lens on it and saw the fine strige, perfectly 
regular, we rejected ZT. //i'a;/<2. Then came the great question — what is 
it? Our first surmise was Helicella affi,nior, Debeaux, from Oran, but it 
could not be that, though near to it, and a similar result was meted out 
to H. cyclostoma, Bourg., from Oran. We could see at once that its true 
affinities were North African, and then we spotted Helicella zakarensis^ 
Kobelt, from Drab-el-Mizan, Kabylie (Algiers), and we cannot separate 
it from this form." Mr. Welch also had some correspondence with Dr. 
W. Kobelt, of Schwanheim, the original finder of the shell in Algiers, 
and I quote below his description of the habitat— "I described Helicella 
zakarensis in the fourth volume of the ' Iconographie,' second series, 
p. 77, pi. no, figs. 659-660, together with the next allied forms, H. calopsis^ 
Bourg., and H. calida, M. The three species form a group confined to 
Mount Zakar, and are not found eastward or westward, where I also 
collected for some weeks. At Cherchel, near the coast, only H calopsis 
is found, and I doubt whether the species may have been transported 
to Ireland from the summit of Mount Zakar, as there is no communica- 
tion between the bains of Hanimam Rizka or Milianoh on the Zakar 
and the coast." Mr. Welch and myself paid a special visit to Rostrevor, 
and searched the spot carefully, on 17th September, 1905, but found no 
trace of any colon3\ Several theories have been advanced in order to 
