126 DEVONIAN FAUNA. 
fragmentary that its true nature can only be surmised, It is distinguished by its 
sharp triangular fold, and by the peculiar grouping of the ribs due to the frequent 
divarication. 
In character it most reminds one of Stricklandinia lirata, but it is too fragmen- 
tary to permit its being referred to this genus with any degree of certainty. 
4. Genus.—RHYNCHONELLA, Fischer, 1809. 
1. RuyNcHoNneLLA acuMINATA, Martin, sp. 
1809. Anomitres acuminatus, Vartin. Petrif. Derb., p. 13, pl. xxxu, figs. 7, 8, 
i 
and pl. xxxiii, figs. 5, 6. 
1865. RiuyncHoneLLA acuMINATA, Davidson. Brit. Foss. Brach., vol. iii, pt. 6, 
1882. — — 
1884. — — 
1885. _— _ 
1886. = — 
1887. _— — 
1889. = = 
p- 60, pl. xin, figs. 16—21. 
— Tbid., ‘vol. v, pt. J, p. 46) plane 
figs. 18—20. 
Tschernyschew. Mém. Com. Géol., vol. i, 
No. 3, p. 21, pl. iii, fig. 14. 
Maurer. Abhandl. Grossh. Hessisch. Geol. 
Landes., vol. i, pt. 2, p. 206, pl. 
vili, figs. 33—36 a. 
Wenjukof. Faun. Dev. Syst. N.W. und Cent. 
Russl., p. 589, pl. v, figs. 9 a, b. 
Tschernyschew. Mém. Com. Geéol., vol. in, 
No. 3, p. 86. 
var. PLATYLOBA, Zoll. Mem. Acad. Sci. St. 
Pétersbourg, ser. 7, vol. xxxvii, No. 3, 
p. 21, pln, tgs, OFl'0! 
Localities.—I have collected many large specimens from Lummaton, and there 
are three in the Woodwardian Museum. From Wolborough there are two in the 
Torquay Museum, three in Mr. Vicary’s Collection, three in the Museum of 
Practical Geology, four in the British Museum, and one in the Bristol Museum. 
Remarks.—It occurs of all shapes; sometimes having a narrow sharp fold and 
compressed sides, sometimes having a broad, rounded, plaited fold, and sometimes 
being very wide and flattened. 
Besides the larger specimens I have found numerous small shells at Lummaton, 
which are more or less lenticular, and seem to be the young of this species. 
