174 Mr. T. D. A. Cockorell on some 



T. vhhxurus, liens. The following synopsis is made from the 

 specimens transmitted by the above-named gentleman : — 



T. Lateral liue continued to the tail. 



A. Dorsal with nine branched rays. 



Depth of the body not more than twice and a half in the total 

 length (without caudalj ; 22 to 28 branched rays in the 



7 

 anal ; scales 34— "S; maculatus. 



6 



Depth of the body more tlian twice and a half in the total 

 length ; diameter of the eye nuich greater than tlie leugth 

 of the snout ; ID to 24 branched rays in the anal ; 

 7—8 



scales 36— :i9 rntilw;. 



5 

 Depth of the body thrice in the total length ; diameter of the 

 eye not exceeding the length of the snout ; IP branched 

 7 



rays in the anal ; scales 3h ohscnnts. 



T 



]}. Dorsal with eight branched rays ; anal Avith sixteen 

 to eighteen. 



Depth of the body more than twice and a half in the total 



length (without caudal) ; scales 35—^7 Ihcrmgxi. 



y— 4 



II. Lateral line not continued to the tail. 



Dursal with nine branched rays ; anal with twenty-one or 

 twenty -two ; depth of the 'body not more than t'R'ice and 

 a half in the total leugth (without caudal); scales 



M— S.=) Ltictleiui. 



[XXIV. — Xotcs on sonie Sj^ecies of Inland Mollusca. 



By T. D. A. COCKEKELL. 



Ariun ater, L. 



The distribution of the colour-varieties of this species is 

 peculiar: a br'ght brick-red form (var. ruhra, Moq.-Tand. 

 1855) appears to be prevalent m Belgium, though, so far as 

 is at present known, it does not occur in Britain. j\Jy 

 brother found it commonly at Brussels, and last year the Hon. 

 Miss M. C. E. Leigh sent me specimens from Spa, together 

 ■with tlie variety Draparnaldi, Moq., and Avion subfusciis, 

 Drap. It is generally supposed that the red forms of Avion are 

 developed in dry situations, while the darker or black varieties 

 inhabit damp and mar.«hy spots ; and this seems to have been 



