a2 Transactions. 
all built up on the same principle, although they may be of 
different size and outline. The model shown is of the Graptolite 
(Monograptus priodon), enlarged about 30 diameters. It may be 
either straight or curved, with a solid axis or stipe, upon which 
the polypery is built. The common canal is well marked, in 
which was contained the cenosare, from which each polyp was 
developed. On the margin of the periderm which surrounds the 
cenosare, the hydrothece or cells are constructed, each individual 
polyp going through the czenosarc to the subsistence of the whole 
colony. The whole of the outside of the polypery is composed of 
a chitinous or horny substance, generally in the course of 
mineralisation, the mouth of the cellule being at the point of the 
denticle, each cell being inhabited by a polyp, and having com- 
munication with the common canal. The simple Monograptus is 
supposed to have four margins or borders surrounding a hollow 
tube, the inner resting on the common canal, which is not 
defined, the superior on the top, or point on which is the cell 
mouth. This description applies to nearly all the other simple 
forms of graptolites. In collecting the above organisms I think 
it is a matter of much importance to procure, if possible, those 
fossils with both their distal and initial points, as they can be 
identified with greater certainty, besides rendering the forms of 
the organisms more complete. 
IIL. A Memoir of the Rev. Mr Gatt, Minister of Graitney, 1727-87. 
By Mr J. Gipson H. Starke, Vice-President. 
The subject of this short notice—the Rev. James Gatt—seems 
to me worthy of having his name recorded in the proceedings of 
this Society, as an eminent parish minister in Dumfriesshire who, 
during his lifetime, was probably as widely known as any among 
his contemporaries ; and whose memory still lingers among a few 
of the present generation. No formal biography of him has ever 
been published, and it is now impossible to obtain sufficient 
materials for this purpose, but from two brief notices of him 
which have been published, and from traditionary accounts, he 
was not only beloved as a minister, but eminent as a scholar. 
The leading events of his life are given in the Paste Eeclesie 
Scoticane, by Dr Hew Scott; and an appreciative sketch of his 
character appeared in ‘‘Good Words” for December, 1876, by 
the Rev. Mr Edgar, formerly minister of Graitney, or, as it is now 
