18 DEVONIAN FAUNA. 



Suture cutting the border very obliquely in front, thence turning rather inwards 

 as it runs up to the eye, and from the back of that tending straight outwards till 

 it meets the border close behind the angle. 



Thorax (and tail) unknown. 



Size of Glabella. — The largest specimen I have seen measures 11 mm. in length 

 without the spines, which are 4 mm. long. It is 16 mm. in width and 9 mm. in 

 depth. 



Localities. — From Lummaton I have obtained forty or fifty specimens, and 

 others were collected by Prof. Hughes and his party of Cambridge geologists 

 during their recent visit to Torquay, and are now in the Woodwardian Museum. 

 There is a specimen from Wolborough in Mr. Vicary's collection. 



Remarks. — This beautiful little species is perhaps the commonest Trilobite at 

 Lummaton, but I have not been successful in finding any specimens of its pygidium. 

 The large rounded concavities that line the glabella and the border, as well as its 

 general shape and peculiar markings, render fragments of it readily recognisable. 

 The setting of the cheek-spine is noticeable ; there seems at least in some instances 

 to be a small notch between it and the corner of the cheek, so that it would appear 

 to start from its side rather than from its angle. The substance of the border 

 seems very massive, but in other parts the test is thin. It appears to be a species 

 which is not liable to great variations. At all events the specimens, fragmentary 

 as they are, seem always to present much the same contours. 



Among the German species there do not seem to be any that are very liable to 

 be confused with the present form. The one which comes nearest to it is G. cera- 

 tophthahna as given by Sandberger. 1 Supposing his figure to be accurate, it 

 differs in two important particulars. It has no vestige of cheek-spines and the 

 lobe of the glabella decidedly overhangs the margin, whereas in the English fossils 

 it ends considerably behind it. There seems, however, no little complication in 

 respect to the German forms of this genus. Sandberger identifies his fossil with 

 Phacops ceratophthalmus, Goldf., 2 and Galymene hydrocephaly, F. A. Rom., 3 following 

 Burmeister in uniting these two species. However, as far as it is possible to judge 

 from drawings, they appear to agree neither with each other, nor with Sandberger's, 

 nor with our own. Goldfuss's original P. ceratophthalmus is reproduced by F. 

 Romer 4, under the name G. Burmeisteri, Barr. 5 (which certainly seems far less like 

 it than several of Barrande's species), evidently under the belief that Goldfusshas 

 figured his specimen with its head curled forwards. Burmeister's 6 figure, how- 



1 1850, Sandb., ' Verst. Ehein Nassau,' p. 23, pi. ii, fig. 4. 



2 1843, Goldf., ' Neues Jahrb. for Min., &c.,' p. 564, pi. v. fig. 2. 



3 1843, F. A. Rom., 'Verst. Harzgeb.,' p. 38, pi. xi, fig. 7. 

 * 1876, Ferd. Bom., ' Letba?a Pal.,' pt. 1, pi. xxxi, fig. 6. 



5 1852. Barr., ' Syst. Sil. Bobem.,' vol. i, p. 484, pi. xviii, figs. 61—71. 



6 1846, Burmeister, ' Org. Trilob.,' Bay Soc, p. 98, pi. iii, figs. 3 and 4. 



