154 MESSRS. A. J. JUKES-BROWNE AND W. HILL I [May 1 896, 



we think it is very likely to be Tr. dunscombensis, for we now know 

 that the beds are of exactly the same age. 



The true Tr. sinuata of Parkinson is only the young stare of 

 Tr. ececenirica, Park., and Lycett states (p. 189) that there is no 

 certain record of Tr. eoccentrica occurring in a higher position than 

 the Blackdown Greensand. Mr. Meyer tells us that he has 

 Tr. excentrica from his Bed 2 (the horizon of the Cowstoms of Lyme 

 Eegis), but that it does not occur in the zone of Ammonites Mantelli. 



Trigonia debilis, Lycett, ' Brit. Foss. Trig.' p. 189, pi. xl. fig. 8. 



This is another species akin to Tr. affinis, but is at present only 

 known from Bed 10 of Mr. Meyer's notation at Dunscombe. 

 Lycett thinks that it is the young of a much larger species, but 

 states that it is quite distinct from the young of any of the known 

 ' Greensand ' species of Trigonia?, glabrae. 



Trigonia crenulata, Lam. in d'Orb., ' Pal. Fr. Terr. Cret.' vol. iii. 

 p. 151, pi. 295. 

 Mr. Meyer has a specimen of this species from Bed 12, obtained 

 from a block on the shore of Pinhay Bay, near Lyme Regis. It 

 is said to be a common fossil in the Cenomanian of Viraoutiers and 

 Gace, as well as near Le Mans, but we only succeeded in getting 

 casts of Trigoniee which might belong to it, or to the next. 



Trigonia crentjlifera, Lycett, ' Brit. Foss. Trig.' p. 189, pi. xl. 

 figs. 1, 7, 9. 

 This was separated from Tr. crenulata by Lycett, the species 

 being founded on specimens in Mr. Meyer's collection. They came 

 from Beds 10 and 11. 'The chief distinction consists in the promi- 

 nent zigzag costellse upon the area and escutcheon,' and the median 

 furrow of the area is a 4 deeply impressed groove ' (op. cit.). 



Trigonia Meyeri, Lycett, ' Brit. Foss. Trig.' p. 125, pi. xxiii. fig. 6. 



A shell belonging to the aliformis group ; it was referred to 

 Tr. abrupta, Von Buch, by Mr. Meyer in 1874, but Lycett gave 

 good reasons for regarding it as a new species, and named it after 

 its discoverer. It occurs in Beds 11 and 12 at Dunscombe and 

 Pinhay, and has also been found in the fossiliferous basement-bed 

 of the Chalk at Chardstock. 



Trigonia Yicartana, Lycett, ' Brit. Foss. Trig.' pp. 141 & 203, 

 with figs, on pis. xxiii., xxv., xxviii., & xl. 



Lycett fully discussed this species, which he distinguished from 

 Tr. Archiaciana, d'Orb. (an Aptien species). He subsequently 

 adopted Mr. Meyer's opinion that Tr. Archiaciana does not occur in 

 the Upper Greensand or Chloritic Marl of England, the Haldon 

 specimens referred to that species belonging in reality to Tr. Vi- 

 aryana. 



Both Meyer and Lycett are inclined to regard the Tr. spinosa of 



