338 Mr. Alder's Supplement to his Catalogue 



In a pond at Whitley Quarries, where it was observed by the Rev. W. Mark and myself 

 in September, 1832. Mr. Mark had previously gathered it, but had placed it in his cabinet 

 without examination. It has been since found by Dr. Johnston in a pond at Holy Island. 



This very distinct species approaches nearest to P. albus, but is smaller, has the whorls 

 more rounded and closer set, and is destitute of the spiral striae. It bears considerable re- 

 semblance to Vaivata cristata, especially in its young state, and is often covered with a 

 dark incrustation. 



For P. Vortex (vol. i. p. 30.), read P. Spirorbis , Mull. 



Further opportunities of examination induce me to believe that the P. Vortex and P. 

 Spirorbis of Muller (Helix Vortex and Spirorbis of Montagu,) are distinct, but it is the 

 latter of these only that is found in this neighbourhood. In summer, when the ditches are 

 dry, the animal closes up its shell with a white epiphragm, within which it lies secure 

 under the mud and weeds in a state of torpidity, until the ditches are again filled with 

 water. Michaud in his " Complement" to Draparnaud's work, has described a species un- 

 der the name of P. leucostomus, on no other apparent grounds of distinction from his P. 

 Vortex, but the circumstance of its forming this curious epiphragm, in doing which it 

 thickens the internal magin of the shell, forming a permanent white rim. As I have ob- 

 served our species to close up the aperture in a similar manner both here and in the south 

 of England, I have little hesitation in uniting Michaud's P. leucostomus and P. Vortex 

 under the PI. Sjnrorbis of Muller, who long ago pointed out the white and thickened aper- 

 ture as an occasional character of his shell, though not perhaps aware of the manner in 

 which it was formed. P. compressus of Michaud, is the P. Vortex of Muller. 



P. complanatus. (vol. i. p. 31.) 

 P. umbilicatus, Mull. 

 Var. a. P. rhombeus, Turt. 

 Found plentifully at Prestwick Car. 



For Auricula (vol. i. p. 31) read Carychium. 



ACME, Hartmann. 

 A. lineata. 



Carychium lineatum, Pfeiffer, Per. 

 C. fuscum, Flem. Jeff. 

 Bulimus lineatus, Turton's Manual. 

 In Moss, Castle Eden Dean, rare. 



Neither the animal nor the shell of this species agrees well with the characters of the 

 <jenus Carychium in which it has usually been placed. The animal, with its long filiform 

 tentacula and proboscidiform head, more nearly resembles that of Cyctostoma, but differs 

 in the want of the operculum. The shell comes nearest to Bulimus, in which genus Dr. 

 Turton has placed it ; but he erroneously intimates that the animal has four tentacula, and 

 entirely overlooks the character of the eyes being at the base of these, which necessarily 

 excludes it from the genus Bulimus. 



SUCCINEA. 



For S. oblonga, (vol. i. p. 31.) read S. gracilis. 

 S. oblonga, Turt. Manual. 



