ANODONTA. 43 



and I suspect that the Doctor mistook this excrescence 

 for a cardinal tooth, and therefore applied the specific 

 epithet " dentatus/^ He omitted any mention of this 

 character in his Dithyra, when he changed the name to 

 " paludosus/^ Var. 2. Scarborough (Bean) ; Otters 

 pool, Lancaster (Tyler) ; Oxwich marsh, near Swansea 

 (J. G. J.). This is the A. ponderosa of C. PfeiflPer. 

 Var. 3. Bog of Allen, Ireland (Humphreys) ; Clumber 

 lake, Notts (J. G. J.). It is the A. Cellensis of C.Pfeiffer. 

 Var. 4. West of Ireland (Humphreys). Var. 5. R. 

 Corfe, Dorset (J. G. J.) ; ponds at Wistow in Leicester- 

 shire, Wynyard Park, Co. Durham, and Oxford (Nor- 

 man). This appears to be the Mytilus Avonensis of 

 Montagu (Test. Brit. p. 172), judging from his descrip- 

 tion and the figure of that species which is given by 

 Maton and Rackett in the ' Linnean Transactions,^ vol. 

 viii. pi. 3. A. f. 4. The shell of this species is also liable 

 to be distorted ; and I have a specimen in which the 

 lower part of the left valve is deeply notched opposite 

 the beak, owing to an injury of the mantle on that side^ 

 the other valve being entire. 



The fry have triangular and pearly shells, which might 

 easily be mistaken for the valves of a Cypris or smaller 

 Entomostracan. The epidermis only is coloured in this, 

 as well as in the other species : the surface of the shell 

 itself, under the epidermis, is white or colourless. 



2. A. anati'na*, Linne. 



Mytilus anatinus, Linn. Syst. Nat. ed. xii. p. 1158. A. cygnea (partly), 

 F. & H. ii. p. 155, pi. xxxix. f. 3. 



Body grey, of different shades of intensity : mantle bordered 

 with dark brown : foot yellowish-grey, or red : cjiUs, greyish- 

 brown. 



* Belonging to {e. g. food for) ducks. 



