232 



under the name of Sol, and by Bolten as Astreea. But I think it 

 should be extended farther, so as to receive hnjperator and Her- 

 coles, Montf., Stellaria, Schmidt, Cyclocantha, Canthorbis, subg., 

 and Tuhicanthiis, Swains., Bolma, Risso, Cookia, Less., and Astra- 

 limn, Phil. 



Umbonium, Link, 1807, I- c. iii. p. 136. 



Spire much depressed ; aperture directed downwards, or to the 

 side, simple ; base showing a convex callus in the place of the um- 

 bilicus. 



Umhonium vestiarium, Linn, sp., and excisum (Chemn. f. 1602). 



That Link's name is to be adopted instead of Globulus, Sebum., 

 or Rotella, Lamck., can hardly be controverted ; although his second 

 species belongs to another tribe. 



Pythia, Bolten, 1798, Mus. (ed. 1819, p. 74); Link, 1807, 1, c. iii. 

 p. 139. 



Whorls, each of them composed of two pieces ; aperture longitu- 

 dinal, toothed on both sides. 



Pythia scarabcBa, Linn. sp. 



This name is preferable to that of Fischer, Polydonta, which, 

 although contemporaiy, is badly made, and wants correction. 



ACEPHALA. 



SuNETTA, Link, 1807, I. c. iii. p. 148. 



Equivalve, in front rather obtuse, closed ; hinge with two cardinal 

 teeth, lateral ones indistinct ; anterior slope shorter than the furrow- 

 shaped posterior slope ; ligament external. 



Simetta scripta (Chemn. f. 261-265)= Cuneus, Muhlf. 1811 = 

 Meroe, Schum. 1817. 



TivELA, Link, 1807, I. c. iii. p. 152. 



Equivalve, longitudinal, without epiderm, closed ; hinge with two 

 cardinal and one elongated lateral tooth ; anterior and posterior slopes 

 equally elongated ; ligament external. 



Tivela vulgaris (Chemn. f. 362). — T. tripla {Fenus), Linn. = 2Vi- 

 ffona, Mulilf. 1811. 



MuscuLiuM, Link, 1807, I.e. iii. p. 152. 



Equivalve, closed ; hinge with two small cardmal teeth, no lateral 

 ones ; anterior and posterior slope nearly equal. 



Musculium lacustre (Tellina), Linn. 



The genus established here, fourteen years afterwards was pub- 

 lished as Pisidium. 



Tentacxjlata. See ' Ind. Gen. Malacoz.' ii. 541. 



Verpa, Bolten, 1798, Mus. (ed. 1819, p. 49) ; Link, 1807, 1, c.iii. 

 p. 159. 



Shell tubular, partly straight, partly winding, at one extremity 

 open, at the other closed by a convex perforated blade. 

 Verpa penis {Sei'pula), Linn. 



