380 



THE YOUNG NATURALIST. 



age. Infancy extends to the twentieth year, 

 youth to the fiftieth, because it is in this 

 period the tissues become firm, virility from 

 fifty to seventy-five, during which the organ- 

 ism remains complete, and at seventy-five old 

 age commences, to last a longer or shorter 

 time as the diminution of reserved forces is 

 hastened or retarded. 



TO CORRESPONDENTS. 



E. H. G,, Sit' ngbc irne. — We are much 

 obliged for the ichneumoned larva of S. 

 Populi, and pu_->a of the ichneumons. 



H. T., Coventry. — Your beetle is Lamia tetor. 



J. H. S., York. — Not being certain about your 

 beetle we submitted it to Mr. Gregson, who 

 names it Tachys (Bembidium) flavipes. 



S. L. Mosley is preparing a collection of 

 lepidoptera found in the neighbourhood of 

 Huddersfield, with interesting notes under 

 each species. The collection will be for 

 public inspection, and a portion of it wiil be 

 ready by Saturday, Sept. 25. 



Young Botanist. — We would recommend 

 Grindon's British and Garden Botany to a 

 non-practical botanist : but why don't you 

 become a practical botanist ? Get Lindley's 

 School Botany. 



EXCHANGE. 



Duplicates. — Ferruginea, C. Nigrum, Sujf- 

 usa, Meticulosa, Trapezina, Affinis, Paphia, 

 Betularia, Bucephala, Quercus, Fotatoria, Hyper- 

 anthus, Polyodon. Desiderata. — Numerous 

 — R. J. Attye, Tac Palace, Storrington, 

 Sassex. 



Duplicates.- F:' if end :1a, and Trifolii, 

 Tritici, Basilinei > :ata, " id males only of 

 Rupicapraria and P/ogeittmaria. — Tom Robson, 

 Bellerby Terrace, Weot Hartlepool. 



On Saturday after. .oon, October 2nd., I 

 shall have about 300 named types of Butter- 

 flies and moths for distribution, and shall be 

 glad to see beginners who are in want of them. 



— S. L. Moslev, Beaumont Park, Hudders- 

 field. 



CONCHOLOGY. 



LAND AND FRESH-WATER SHELLS 

 By H. T. Robson, Stockton-on-Tees. 

 [Continued from page 311 J 

 Genus, Ancylus. 



This genus comprises our two species of 

 fresh -water Limpets, the shells are not formed 

 of whorls, like the preceding genera, but are 

 conical or cap-shaped. The animals have 

 broad heads with a pair of small triangular 

 tentacles, at the inner corner of which the 

 eyes are placed. The two species are 

 Fluviatilis and Lacustris. 



Pluviatilis- — The shell is very small, only 

 about a quarter of an inch long, conical, the 

 base being oval, and the height something like 

 half as much as the length, the apex is not 

 central but towards the back of the shell, is 

 slightly hooked and turned towards the right; 

 the shell is whitish, covered with a pale brown- 

 ish epidermis, it is finely striated, the striae 

 radiating from the apex. It may be found in 

 all parts of the country in streams, lakes, &c, 

 generally adhering to stones. 



Lacustris. — This is of similar form to 

 the last, but it is narrower, without the radi- 

 ating striae, and the apex is turned towards 

 the left. It is found in lakes, ponds, and 

 canals, generally upon water plants. 



THE GENERA AND SPECIES of the 

 tribe Inoperculata, or the Univalves which an 

 without an operculum have now been namet 

 and briefly described, and we come next to those \ 

 Cephalsor Univalves which have an operculum,; 

 forming the tribe Operculata, they are not 

 numerous, and, as was mentioned previously, 

 the land shells especially are very few, there] 

 being only two British species. 



The Operculum, which is the chiefj 

 characteristic of the tribe, has already beeni 

 described as a shelly or horny plate. 



