56 
THE GEOLOGIST. 
discovered at Bowertrapping, in Scotland ; and which I was happy, 
to recoo-nise among some duplicates kindly presented to me by Mr. 
Young. Prod. Griffithutmis de Koninck has been recorded by Mr. 
MoiTis and others as a British species ; but no examples referable to 
that shell have come under my observation. We need not prolong 
our observations with reference to the other well-kno^\^l species of 
this important genus, but pass at once to Clwnetes, for its species 
appear still involved under considerable confusion, and will require 
much farther investigation under favourable circumstances before 
they can be properly or satisfactorily arranged. The difficulty is 
principally caused by a number of badly defined so-termed species, 
fabricated in Ireland and America on insufficient material. 
The only British species which I have been able to recognise ^vith 
any degree of certainty are G. comoides, C. painlionacea, G. Bucliiana, 
G. Hardrensis, and perhaps G. Dalmaniana ; but I am still uncertain 
with reference to this last, (although we possess examples identical 
with those of Belgium,) on account of the great resemblance certain 
specimens bear to others of G. ^apilionacea. G. Bucliiana appears 
to be a well marked species, on account of its fewer or stronger libs ; 
but these also vary to a considerable extent. It is quite evident that 
the shell figured as Lejjt. crassistria, by Prof. M'Coy, in the " British 
Pal. Fossils" is a synonym of G. Buchiana; but I am still under some 
uncertainty whether the typical form of G. crassistria, published in 
the " Synopsis," be really the same. Anyhow, on account of its 
fewer and simpler ribs, it will be preferable to provisionally locate 
both it and G. tuhercidata under G. Bucliiana as uncertain varieties. 
The next difficulty is in the determination of what are the synonyms 
of the good species for which we have retained the designation of 
G. Hardrensis, and of which G. suh -minima' and G. gihberula in M'Coy 
are evidently synomyms; but I would not venture to speak with so 
much confidence with reference to G. volva, G. sidcata, G. imiata, and 
G. serrata, M'Coy, all established on imperfect Irish specimens ; 
but it is at the same time highly probable that if not all, the greater 
number are simple variations in shape of a single species. All we 
know of G. sulcata consists of a single ventral valve. G. (L&pt.) serrata 
is fabricated from not even half of a similar valve ! G. volva bears 
much resemblance to G. Hardrensis ; while G. perlata is perhaps also 
a small variety of the same ? C.poUta, M'Coy, although described as 
smooth ? looks very like many examples of G. Hardrensis or G. volva ? 
in which the ribs are somewhat obliterated. It would therefore 
be impossible with the scanty material at my command ; and in the 
present state of our information to determine which of these Irish 
forms are species or synonyms ; and it would therefore be very desir- 
able that Irish geologists or collectors should carefully assemble 
numerous specimens of Glionetes from the localities where the 
so-tei-med species were mentioned to occm\ The G. Laguessima 
stated to occur at Der^vick in England, and Rahoran in Ireland, is 
probably also nothing more than a variation of Hardrensis ? Having 
done all that was within my power to clear up these difficulties, 
