114 DEVONIAN FAUNA. 
IV. Family.—Arryripa, Dall, 1871. 
1. Genus.—Guassia, Davidson, 1881. 
1. Guassta Warppornel, Davidson. Pl. XII, figs. 7, 7 a, 9, 9a, 9d. 
? 1872. RuyncHoneLta Beyricul, Kayser. Zeitsch. Deutsch. Géol. Gesell., vol. 
Xxlv, p. 678, pl. xxvi, figs. 6a—k. 
1882. Gtassta Wurpzornet, Davidson. Brit. Foss. Brach., vol. v, pt. 1, p. 38, 
; pl. i, figs. 1O—14. 
? 1885. — Bryricut, Maurer. Abhandl. Grossh. Hessisch. Geol. Landes., 
vol. i, pt. 2, p. 192, pl. viii, figs. 11—15. 
Localities—This shell seems rather rare at Lummaton. In my Collection 
are about thirty specimens, in the Woodwardaian eight, in the Torquay Museum 
one, in the British Museum one, and in the Bristol Museum one, which seem, as 
far as can be judged, to belong to it. There also seem to be five specimens from 
Wolborough in the Museum of Practical Geology. 
Remarks.—It is almost impossible to distinguish this species by external 
characters alone from small examples of Waldheimia Whidbornei, Davidson. The 
type-specimens were, I believe, operated upon by Mr. Glass, after having been 
drawn by Dr. Davidson, and therefore were destroyed as types as far as the 
exterior 1s concerned. 
Maurer doubtfully refers this shell to the species described by Kayser as 
Rhynchonella Beyricht. Kayser had informed him that he thought his shell 
probably belonged to the genus Gilassia; and a specimen of it, afterwards 
discovered, proved this view to be correct. He states that the German shell has 
a less arched beak than the English form, that its spire is more circularly twisted, 
and that its last whorl lies nearer to the body, but he thinks these differences 
perhaps only indicate a local variation. It also seems to have a much larger 
foramen. I cannot see any distinction from the present species in the shell which 
he refers to Glassia obovata, Davidson. 
2. Genus.—Atrypa, Dalman, 1828. 
]. ATRYPA RETIOULARIS, Linné, sp. Pl. XIII, fig. 10. 
1767. ANoMIA RETICULARIS, Linné. Syst. Nat., ed. xii, p. 1152. 
1864. ATRYPA RETICULARIS, Davidson. Brit. Foss. Brach., vol. iii, pt. 6, p. 53, 
pl. x, figs. 3, 4. 
