174 TRANSACTIONS, NATURAL HISTORY SOCIETY OF GLASGOW". 



species by the shores of Loch Fad is the more 

 interesting, seeing that Haddin, as he states in his 

 paper, failed to observe any Helicidae at all along 

 these shores. After referring to the distribution of 

 several of the Helicidse, he says : "It will be observed 

 from the preceding remarks that I have not been 

 able to record a single species from the banks of 

 Loch Fad, while on the shores of Loch Ascog and 

 Loch Greenan are found Zonites nitidus," etc. He 

 then goes on to say : " The reason of this I would 

 not venture to affirm, but it is a fact worthy of 

 note that the banks of the former are formed of 

 shale, while those of the latter are of sand." I am 

 quite at a loss to understand how it happened that 

 Haddin failed to observe any Helicidse on the shores 

 or banks of Loch Fad, though his misapprehending 

 their geological conditions might be more easily 

 explained. The only plausible reason I can offer is 

 that he had examined the shores of Loch Fad at a 

 time when the weather was hot and dry, and when, 

 as might be expected, few if any molluscs would be 

 seen, whereas the very different results obtained by 

 me were owung to the examination having been 

 made in the morning "while the air was cool and 

 moist. As has been stated, a good nvimber of species 

 were observed, but they were nearly all of the 

 commoner kinds — Vertigo suhstriata, V. antivertigo, 

 and V. edentula being the only ones that could be 

 considered uncommon or rare. As regards Loch 

 Fad itself, although I got a boat and dredged a 

 part of the loch, only the common aquatic forms 

 were observed, as will be seen by referring to the 

 list at the end of this paper. 



Before leaving Loch Fad, it may be stated that in 

 a little patch of marshy ground on the south-east 

 side, and about a quarter of a mile south-west from 

 the embankment, an Ostracode was observed which 

 had been known previously only as a Post- tertiary 

 fossil under the name of Cypris hi'owniana, Jones. 

 The examination of living specimens from this 



