TRIGONIA. 73 



and hinge-area; it is therefore possible that this form may belong to Pedun- 

 culus. 



Distribution. — Chalk Rock (zone of Heteroceras Beussianuin) of Cuckhamsley. 



Famlliz—TmaomiBM, Lamarck. 



Genus — Tiugonia, Bruguiere, 1789. 

 ('Encyc. Meth. Vers.,' vol. i, p. xiv ; Lamarck, ' Syst. Anim. sans Vert.,' 1801, p. 116.) 



The British forms of this geuus have already been considered in detail by Mr. Lycett in his 

 ' Monograph of the British Fossil Trigoniae,' published by the Palseontographical Society in 1872-9 ; 

 it will therefore not be necessary, in the present work, to do more than enumerate the Cretaceous 

 species, and to give some additional notes on their affinities, synonymy, etc. 



Section 1.— Scaphoide^. 

 Teigonia scapha, Agassiz, 1840. Plate XX, figs. 1, 2. 



Additional Synonymy. 



1861. Teigonia hunstantonensis, H. Seeley. Ann. Mag. Nat. Hist., ser. 3, 



vol. vii, p. 123, pi. vi, fig. 9. 

 1877. — SCAPHA, Lycett, p. 183, pi. xxxviii, fig. 6. 



1884. — — O. Weerth. Die Fauna Neocom. im Teutoburg. Walde 



(Palaeont. Abhaudl., vol. ii), p. 45. 

 1896. — — A. WoUeiiiann. Zeitschr. d. deutschr. geol. Gesellsch., 



vol. xlviii, p. 846. 

 1900. — — — • Die Biv. u. Gastrop. d. deutsch. u. 



hollJind. Neocoms. (Abhandl. d. k. 



preussisch. geol. Land., N. F., 



pt. 31), p. 92. 



(iii) Z. radiata. Alth, ibid., p. 234, pi. xii, fig. 19 ; Favre, ibid., p. 122, pi. xii, fig. 13. 



(iv) L. plana. Eomer, ' Die Verstein. des norddeutsch. Kreidegeb.' (1841), p. 69, pi. viii, fig. 24 ; 

 Griepenkerl, "Senou. Kreide von Konigslutter," ' Palseont. Abhandl.,' vol. iv (1889), p. 56. In this 

 form the valves appear to be flatter and the umbones less prominent than in the English species 

 described above. 



(v) Pectuneulus? insculptus, Keuss, ' Die Verstein. der bohiu. Kreideformat.,' pt. ii (1846), p. 8, 

 pi. XXXV, tig. 5 ; Fritsch, ' Stud, im Gebiete der bohm. Kreideformat., v. Priesener ISchichten ' (1893), 

 p. 93, fig. 106. 



10 



