April, iSgi.] THE BRITISH NATURALIST. 



6i 



Pisidium. — These unfortunate little bivalves are much misunderstood 

 in this country, if Dr. Westerlund is correct. P. fontinale, Drap., is a 

 synonym of P. piisilliun ; but we may use the name as before, writing 

 P. fontinale, C. Pfr. (non Drap.) Clessin's fossavinum is said to be 

 ■fontinale : but cinereum, Alder, is a variety of P. casertanum, Poli, of 

 which sinuatum is a monstrosity. P. henslowammt, P. pulchelhim, P. 

 pallidum, and P. obtusale, are all regarded as species. P. ptisillum, v. 

 ventrosum, is referred to P. scJioltzi, Cless., var. trigonatum, Wst. P. 

 pusillim of Jeffreys is said to be P. globulare, CI. ; but the genuine 

 ptisillum is considered also British. P. roseum of Jeffreys is not Scholtz's 

 species of that name, but is P. niilinni, Held. P. fecluzianum, Bourg., 

 is a very doubtful species supposed to occur in Ireland. 



Unio. — The Linnean pictornm is perhaps a form of tumidus, and so 

 our species of that name is called U. rostratus, Lam. U. sinnatus, Lam., 

 is referred to U. aunciilavius, Spengler. Locard is quoted on Mav- 

 garitana elongata, Lam., which is British, but it is only a form of U. 

 mavgaritifev. U. arcuatus, Bouch., is U. houchardi, Bgt. 



Anodonta. — The following so-called species are British : — A.browni, 

 Bgt. (Northumberland, founded on a figure of Brown's) ; A. fnscata, 

 Fer. (not described); A. gallica, Bgt. (= Brown's cellensis); A. mactdata, 

 Shepp. ; A. racketti, Bgt. (= Brown's ponderosa var., " 111. Conch. 

 Brit.," 1845, pi. 15, f. i) ; A.fallax, Colb. (= anatinus var., f. 4, Mat. 

 and Rack., Linn. Tr., 1807); A. dentata, Turton (probably an abnormal 

 cygnced) ; A. paludosa, Gray ( a cygncea-iorm) ; and A. dupuyi, Ray and 

 Drt. In addition to these, the following forms — considered by us as 

 varietal only, which have been recorded from Britain — are given as 

 species : — A. radiata, Mull. (sp. dub.); A. incrassata, Shepp. sp. dub.); 

 A. rostmta, Kok. ; A. stagnalis, Sby. ; A. stnrmi, Bgt. (= intermedia) ; 

 A. avonica, Sgt. {= avonensis) ; A. subrJwmbea, Brown (sp. dub.) ; A. 

 contorta, Br. (sp. dub.); A. cellensis, Gmel. ; A. ventricosa, C. Pfr.; A. 

 arelatensis, Dup. ; A. pictetiana, Mort. ; A. rayii, Dup. ; A. scaldiana, 

 Dup. ; A. inilleti, R. and D. ; and A. minima, Mill. Whether all of 

 these are really found in this country is perhaps open to question. 

 Our anatina, vars. coniplanata and normandi , are both considered valid 

 species, and placed in the sub-genus Pseudanodonta, Bgt. It should 

 be mentioned that Dr. Westerlund gives two species as A. rayi, and 

 the rayi (Mab.,) Bgt., ought, therefore, to have a new name— that is 

 if either or both are to be considered true species. Similarly, Limncva 



