PHACOPS. 17 



General form broad-oval, not very convex. Length occasionally If inch. Head 

 smooth, semicircular, deeply trilobed, the lateral angles rounded. Glabella very broad in 

 front, spherical-triangular, occupying much more than one third the width of the head ; 

 convex, but not gibbous, and overhanging the front ; neck-furrow strong, basal lobe 

 distinct, and with two lateral tubercles, the rest of the lobes obsolete. Cheeks triangular, 

 evenly convex, with a narrow margin, which is strong at the rounded angles, and lost in 

 front of the glabella; the neck -furrow strong. (Eyes absent in our English specimens, 

 but probably present in perfect individuals.) 



Thorax of eleven segments, with convex narrow axis and rounded pleurae ; the 

 segments of the axis tuberculate at the sides ; the pleurae not much bent back, rounded 

 at the end, the groove narrow and short, the fulcrum placed at less than half way out 

 from the axis; facet rather large. Tail short, transverse, flattened, arched in front, 

 straighter behind, about as long as the axis of the thorax is broad, and more than twice as 

 wide as long, of few joints, the axis conical, and reaching nearly to the margin, blunt at 

 the tip, and with four or five rings. The sides wide, with not above four furrows, which 

 do not reach the margin, and are faintly interlined with other furrows. 



Localities. — Upper Devonian. Knowl Hill, Newton Bushell ; specimens figured from 

 Mr. Pengelly's cabinet (figs. 5, 6), and Mr. Vicary's (fig. 7). I distrust the other 

 South Devon localities given in the " Pal. Foss.," viz., Mudstone Bay and Durl- 

 stone. But it is probable the species occurs at Brushford, North Devon, as 

 quoted by Professor Phillips. 



P. cryptophthalmus, Emmerich ? PI. I, fig. 8. 



Phacops cryptophthalmus, Emm?\, in Leonbard und Bronn's Jahrbuch., 1845, pp. 



27, 40, &c. 



— — Roemer. Palseontographica, vol. iii, pi. vi, p. 14 (bad 



figure), 1854. 



— — Sandberger. Verst. Rheinisch. Schicht. Syst., t. i, fig. 6 



(exclude his synonyms, as he includes several species, 

 among others, the P. Icevis figured above), 1850. 

 Phacops limbatus, Richter? {fide Sandberger). 



" P. capite semiorbiculari, later ibus frontis rectilineis, ad angulwm acutum convergentibus. 

 Annulus fere recfilineus. Oculi parum evexi. Thorax latus. Pygidium breve obrotun- 

 datum, ex articulis 8, pseudopleuris 5, composition. Superficies subtilissime granulata." 

 Sandberger. 



I suppose this to be the species given in Sandberger's beautiful plates. The character, 

 " eyes but little prominent," well agrees with this species. He figures the eyes as lunate., 

 and with fewer lenses than our Newton specimen. But the shape of the glabella is the 

 same, and I do not see that there is much room for doubt. 



Locality. — Upper Devonian : Newton Bushell (Mus. P. Geology). 

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