286 The Irish Naturalist. [Nov,, 



opinion of the great modern Swedish conchological authority should be 

 carefully considered. Even if we should not all agree with the propriety 

 of Dr. Westerlund's applying the name of a distinct species {^H. lampra) 

 to the Aran Island form of H. ericetorum, some reference to it might 

 have been made. 



Although some of the figures, such as that of Linnuva invohita, are 

 poor, they are on the whole satisfactory, and no one can help admiring 

 the beautiful plate X. containing the Pisidia, a genus which is a sore 

 trouble to the conchologist. It would have been well to place the 

 figures of the shells of Testacella haliotidea and T. Matigei on plate II., 

 instead of moving them to plate VII., where they are apt to be 

 overlooked. 



In speaking of the size of slugs (p. 2) it is misleading in the highest 

 degree to say that they measure so many millimetres '■^ from the nose to the 

 extremity of the keel,"" since if slugs have an organ of smell at all, it certainly 

 is not at the extreme anterior end of their body, whilst only few possess 

 what may be called a keel. 



Mr. Adams has in many ways made it easier for students to identify 

 the British species of slugs, but it is doubtful whether any one could dis- 

 tinguish Arioji ater from A. miniums, after reading the description on 

 page 27. The latter cannot be at once identified, as Mr. Adams says it 

 can, by its lateral bands, since it is more often without than with such ; 

 and Arion ater is certainly not without bands ; during its youth, banded 

 forms are the rule and bandless ones exceedingly rare. 



Before we conclude our criticism of Mr. Adams' work, we should like 



to say a few words on the list of the "authenticated" records of the 



distribution of British land and freshwater mollusca given at the end. 



It appears that records are "authenticated " if the specimens have been 



seen by one out of the three following conchologists, viz., Mr. Taylor, 



Mr. Roebuck, and the late Mr. Ashford. Apparently such records as 



even those of the late Dr. Jeffreys would be rejected as not authenticated. 



The great merit of this system of authentication is supposed to lie in 



the uniformity of value which it gives to the records, but it is certain 



that there are many conchologists in the British Islands who are just as 



capable of identifying most of the British species as the gentlemen above 



mentioned. Would it not be a better plan in order to quickly arrive 



at the distribution of land and freshw^ater mollusca throughout the 



British Islands to enlarge the body of referees, and ask them to select a 



few of the critical species which should always be submitted to specialists 



before entering them as authenticated records ? 



A few defects and deficiencies in special parts of this work cannot, 

 however, seriously detract from its value and importance. The print is 

 excellent, and the book may be confidently recommended as the best 

 existing collector's manual on the British land and freshwater mollusca. 



R. F. S. 



