2So 



HARDWICKE'S SCIENCE-GOSSIP. 



var. alba. It occurs in company with H. caperata, 

 and it is interesting to record that I have taken a 

 single specimen of Caperata similarly banded on the 

 same bank. In September I also took this variety 

 of H virgata at Brixham (Devon), sparingly, and 

 observed that the banding of the transparent shells 

 was exactly the same as that of the coloured forms 

 with which it lived. Sufficient specimens were 

 obtained of either kind to distinguish the predomin- 

 ance of vars. bifasciata and leucozona. Next to these 

 ranked the type. The only other locality where I 

 have ever met with H. virgata var. alba is near 

 Bordeaux Harbour, Guernsey, also I believe an un- 

 recorded habitat. — Brockton Tomlin. 



H. Nemoralis, var. sinistrorsum. — While 

 collecting shells at West Drayton this summer I came 

 across a sinistral Helix nemoralis. The specimen is 

 a dead one, and has a small hole punctured in the last 

 whorl, otherwise it is in fairly good condition and 

 scarcely bleached. Besides varieties of Nemoralis I 

 have found here //. arbustorum and sericea in profusion. 

 — F. G. Fenn, Isleworth. 



Helix Nemoralis, var. Hortensis. — The shell 

 thus labelled in the Hartley Museum, Southampton, 

 is a well-known form, and the name appears in all 

 standard works on Conchology and in most of the 

 reputed lists — sometimes as a species and sometimes 

 as a variety. It differs from Helix nemoralis in 

 being smaller, in having a white lip, and with a 

 dark stain on the columella. Opinion is about 

 equally divided as to jits being a good species, but 

 having regard to the intermediate forms, and for the 

 convenience of systematists, I think the balance is in 

 favour of according it generic rank. — J. T. Marshall, 

 Sevenoaks, Torquay. 



Helix Nemoralis (var. Hortensis). — In 

 answer to Mr. McBean, this shell should be Helix 

 hortensis. It was customary with the older workers 

 to consider it merely a variety of Helix nemoralis and 

 not a distinct specific form. That will account for 

 the discrepancy of the nomenclature of the land and 

 fresh-water shells used in the Hartley Museum and 

 in our more modern text-books. To-day it is 

 recognised as a distinct species, not only on account 

 of the smaller, and more conoidal form of its shell 

 and its white or rose-coloured peristome, but also on 

 account of the differences between the two forms in 

 their internal anatomy, especially in the odonto- 

 phoral membrane or radula, the shape of the 

 spicnlum amoris, and the number and character of 

 the digitate glands. In my " Handbook," to which 

 Mr. McBean refers, Helix hortensis and its varieties 

 will be found described on p. 1 1 1 ; Helix nemoralis and 

 its varieties on pp. no and in.— J. IV. Williams. 



Anodonta Cygnea and Anatina. — I had ex- 

 pected Mr. Williams replying to Mr. W. M. Webb 

 on this subject touching the distinctness of Anodonta 



cygnea and anatina. Failing any answer from Mr. 

 Williams I may just point out, that the "weight of 

 evidence " is greatly in favour of the two forms being 

 separate species. Mr. Webb has adduced Gray, 

 Forbes and Hanley, Isaac Lea and Dr. Henry 

 Woodward as authorities holding that anatina is but 

 a variety of cygnea. Against Mr. Webb's authorities 

 I set the following : Lamarck, Fleming, Mac- 

 gillivray, Alder, Bean, Jeffreys, Taylor and M. 

 Drouet. I believe all these well-known concho- 

 logists have regarded the smaller, angular, winged, 

 and usually greenish form of anodon we call anatina 

 to be a distinct species. Dr. Woodward and a few 

 other antediluvians, who have a strong dislike to 

 the trouble and expense of rearranging their cabinets, 

 might as well argue that all the species of conti- 

 nental anodons are one, and that Unio tumidus, 

 Unio pictorum and Unio ovalis are all one, because 

 there are a few difficult graduating forms be- 

 tween each two species. Helix nemoralis and Helix 

 hortensis were one till proved by their darts to be 

 two. — George Roberts. 



Sense of Smell.— Anent the opinions lately ex- 

 pressed in our daily papers and journals as to the 

 value of dogs as trackers of criminals, I am of 

 opinion that even the feeble trials of indifferently 

 trained, and in some cases altogether untrained 

 animals, have been sufficient to prove that some of 

 our canine friends are eminently qualified for detec- 

 tive work. Sensory impressions are very strong in 

 the canine race, and although traffic and other causes 

 may have obliterated in some places the scent to be 

 followed and given rise to other effluvia— yet (especi- 

 ally in well-trained dogs), the impression first made 

 upon the organ of smell, is, I believe, retained 

 sufficiently long to enable the animal to pick up the 

 trail under great and seemingly insurmountable 

 obstacles. The extremely moist state of the mucous 

 membrane lining the nasal passages in the dog 

 intensifies the various odours which are conveyed by 

 the respiratory current through the nostrils, and this 

 is especially so in connection with the thin delicate 

 olfactory mucous membrane which is supplied with the 

 special nerves of smell whose function is to receive 

 odorous impressions and transmit them to the ence- 

 phalon. In blood or sleuth hounds, and also in the old 

 southern hound, the olfactory mucous membrane is 

 highly sensitive— thus accounting for the keen sense 

 of smell in these breeds and their adaptability for 

 tracking "by nose." ' — Woodroffe Hill, F.R.C.V.S. 



NOTES AND QUERIES. 



Ferns. — The proliferous ferns described by your 

 correspondent, E. E. Lowe, may have been planted 

 there by the owner, who might have been collecting 

 such varieties. It is rather surprising that Scolopen- 

 drium was not amongst the number of sports, as it is 



