10 DEVONIAN FAUNA. 



Class— CRUSTACEA. 



Sub-class— ENTOMOSTEACA, Mnller, 1785. 



Order— TRILOBITA, MacLeay, 1839. 



I. Family — Phacopid^, Salter, 1864. 



1. Genus — Phacops, Emmerich, 1839 (emended, 1845). 



1. Phacops latifrons, Bronn, sp. PL I, figs. 7 — 10, and PI. II, figs. 1 — 4. 



1844. Phacops latifeons, Ferd. Homer. Rhein. Uebergangsgeb., p. 81. 

 1864. — — Salter. Mon. Brit. Tril., p. 18, pi. i, figs. 9—16. 



1869. — — Verneuil. Append. Faun. Dev. Bosph., p. 16. 



1872. — — Kayser. Zeitsch. Deutsch. Greol. Gesell., vol. xxiv, 



p. 661. 

 ? 1885. — — Maurer. Abhandl. Grossh. Hessisch. Geol. Landes., 



vol. i, pt. 2, p. 262, pi. xi, figs. 27—30. 

 1889. — — Whidhorne. Mon. Dev. Fauna, vol. i, p. 6, pi. i, 



figs. 8, 9. 



Size. — The largest English specimen which I have seen (locality unknown), 

 exceeds five inches in length. 



Localities. — The specimens are almost always either detached heads, bodies, or 

 pygidia. In the Museum of Practical Geology are four from Croyde, one from East 

 Hill, Braunton, three (including a head figured by Salter) from New Road Quarry, 

 Pilton, and one from Baggy Point. In the Barnstaple Athenaeum are 2 from 

 Saunton, 3 from Pilton, 10 from Top Orchard, 1 from Bradiford, 1 from 

 Brushford, 5 from Kingdon's, Shirwell, and 1 from Roborough. In the Porter 

 Collection are 4 from Pilton, 1 from Top Orchard, and 1 from Poleshill. In 

 the Woodwardian Museum are 16 from Top Orchard, 1 from west of Saunton 

 Court, 1 from south-west of Sloly, and 60 from Barnstaple. In the British Museum 

 are four from Marwood and Barnstaple. 



Remarks. — As the specimens of this well-known Trilobite from these beds, 

 though so numerous, are all imperfect, and generally distorted, I have for the 

 present deferred attempting a detailed description of them, especially as the 

 species has already been fully described by Salter in his Memoir published by the 

 Palaeontographical Society. 



It appears to me that all the above-named specimens most probably belong to 

 the present species, though they vary very greatly in size, and have in some cases 



