42 



THE CONCHOLOGIST. 



ACME, Hartmann. 



Acme lineata, Drap. 



" After many searches for this rare species, 

 I discovered five specimens among moss 

 growing on a clump of Carex paniculatn, 

 by a stream running through the boggy 

 swamp at the foot of Well Copse." (S. 

 Spencer Pearce.) 



Although I have .searched most carefully, 

 in different parts of the county, I have not 

 as yet had the good fortune to meet with 

 this species. 



SPILKRIID/l':. 



It is much to. be regretted that so little 

 attention has been paid to this family by 

 English conchologists. With the exception of 

 Jenyns' work, and a few scattered writings 

 of various authors, little or nothing has 

 been written by our own countrymen. Why 

 this is so it is difficult to say— the SpInei iidce 

 present quite as many points of interest as 

 any other family, and are an exceedingly 

 variable one. K careful study of the 



variation alone, would well repay whatever 

 time and trouble were given. A large 

 number of varieties of both Sphccriiuii and 

 Pisidiuin have been described by American 

 and continental conchologists, a number of 

 which will no doubt be found to occur in 

 our own country. 



Although such diversity of opinion exists 

 amongst the students of this family, hardly 

 any two agreeing as to the limits of specific 

 range, much might be done to place their 

 nomenclature in a better and more satis- 

 factory condition. Mr. H. E. Quilter, of 

 Leicester, is, I understand, devoting some 

 little attention to comparing a number of 

 fossil forms with recent ones, and would 

 be very pleased to receive the loan of any 

 forms he does not possess. 



The life - history has not, that I am 

 aware of, been worked out by anyone. 

 I have made some attempts at breeding 

 them, but they have as yet proved anything 

 but satisfactory. 



The following observations on Sp/ncniini 

 Cornell )ii may possibly be of interest : 



" In Dr. Jeffrey's ' British Conchology,' 

 p. 15, Vol. I., there appears an extract 

 from a letter received from Dr. Eukis, of 

 Guernsey, referring to the habits of the 

 SphcEriidcE. In speaking of cor>ien/n as a 

 thread-spinner. Dr. Lukis says : Cyc/as cornea 

 is much less active or inclined to ascend 

 the glass ; in fact, I have not seen it 

 accomplish the feat." I have ior some 

 short time kept a number of this species, 

 and have found it quite the reverse of the 

 above. One specimen which I noted care- 

 fully spun in the space of four hours three 

 distinct threads, from 2^- to 3 inches in 

 length ; another spun two, about 3 inches 

 long, in about two hours and a half 

 Dr. Lukis states that it took .V. lacitstrc 

 three hours to spin a thread one inch in 

 length. This statement cannot apply gener- 

 ally to the Sp/hcriidcc, as I have at least a 

 dozen separate observations recording threads 

 of 2^ to 4 inches, none of which took 

 more than seven hours to spin " (Science 

 (iossip, June 1890, p. 140). 



SPH.ERIUM, Scopoli. 



Sphaerium corneum, L. 



Very common and well distributed through- 

 out the county. 



Var. flavescens, McGill. 

 Fairly common ; generally found with ty[)e. 



Var. scaldianum, Norman. 

 I Thames at Clifden Hampden. (J. G. J., 



I B. C). 



