PHILLIPSTA. 11 



been referred to Phacops granulatus, or Trimerocephalus Isevis. Some of the 

 specimens in the Woodwardian Museum are at first sight very different, being 

 apparently shorter with narrower segments and a narrower axis, but my 

 impression is that these differences are entirely due to distortion. Even the very 

 small heads appear to have the usual obtuse and perpendicular front margin 

 characteristic of this species, and not the subangular and protruding fronts seen 

 in T. granulatus from South Petherwyn. 



Again, as a specimen in the Museum of Practical Geology labelled T. laevis, 

 Miinster, sp., from Brushford, which was probably the grounds for Salter's 

 recording that species from these beds, appears to be exactly similar to our other 

 specimens, I am inclined to delete that species from the Pilton list. 



The coarse granulation, absence of furrows, and great width and shortness of 

 the glabella, and especially its unprotruded perpendicular front, seem to be some 

 of the distinguishing marks of the species. The axis of the pygidium shows 

 tubercles in well-preserved specimens. 



Affi^iities. — P. Potieri, Bayle,^ seems to have a narrower, more protruding, and 

 more finely granulated glabella. 



P. rana, Green ,^ has finer tubercles on the glabella and more segments in the 

 pygidium. 



P. altaicus, Tschernyschew,' has a longer glabella, with a more convex and 

 protruding front, and more segments in the pygidium. 



II. Family — PROETiDiE, Barrande, 1852. 

 1. Genus — Phillipsia, Portloclc, 1843. 

 1. Phillipsia Hicksii, n. sp. PI. II, figs. 5 — 8. 



Description. — General form very elongate, ovate ; in section deep. Thorax 

 relatively large, the proportionate length of head, thorax, and tail being about 

 5 mm., 8 mm., and 5 mm. 



Head-shield small, nearly semicircular. Glabella large, subcylindrical (i. e. 

 considerably elevated, with straight sides and rounded anteriorly), reaching to the 



1 1878, Bayle, ' Explic. Carte Geol. France, Atlas,' pi. iv, figs. 7—10 ; and 1889, Kayeer, ' Abhandl. 

 Kon. Preuss. Geol. Landes.,' n. s., pt. 1, p. 67, pi. x, figs. 5, 6 ; and pi. xxiii, figs. 1 — 6. 



2 1832, Green. ' Mon. Trilob. N. Amer.,' p. 42 ; and 1888, Hall, ' Pal. N. T.,' vol. vii, p. 19, pi. vii, 

 figs. 1 — 11 ; pi. viii, figs. 1 — 18 ; and pi. viii a, figs. 21 — 33. 



•^ 1893, Tschernyschew, ' Verhaudl. Russ. Kais. Miner. Geaell.,' vol. xxs, p. 4, pi. i, figs. 1 — 5. 



