PHILLIPSINELLA PARABOLA. 85 



Group (Cambrian) of the Eureka district, but it seems doubtful whether this 

 American form is really attributable to Barrande's genus. 



Dimensions. — Length of head-shield, 3'0 mm. 



Collection. — Mrs. Gray. 



Horizon and Locality. — Balclatchie Group (Llandeilo) : Balclatchie. 



Genus PHILLIPSINELLA, Novak. 

 1. Phillipsinella parabola (Barrande), 1846. Plate XII, figs. 1, la, 2. 



1846. Phacops parabola, Barrande, Nouv. Trilob., p. 6. 



1852. Phillipsia parabola, Barrande, Syst. Silur. Boheme, vol. i, p. 477, pi. xviii, figs. 24 — 29. 



L869. Phillipsia parabola, Linnarsson, Oin Vestergotl. Camb. Silur. Aflagr., p. 72, pi. ii, figs. 30 — 32. 



1872. Phillipsia parabola, Barrande, op. cit., Suppl., p. 18, pi. i. 



1884. Phillipsia parabola, Novak, Z. Kemit. bohm. Trilob., p. 27 (Beitr. z. ralacont. Osterreich). 



1885. Phillipsinella parabola, Novak, Stud. Hypost. Ill (Sitz. K. bohm. Gesell. Wiss., Jahrg. 1885), 

 p. 581, pi. iii, figs. 1 — 3. 



1885. Phillipsinella parabola, Marr and Boberts, Quart. Journ. G-eol. Soc, vol. xli, p. 47G. 



Pit il I ipsella parabola, Oehlert, Bull. Soc. Et. Scient. Angers, pp. 11, 21, pi. ii, fig. 38. 

 189G. Phillipsinella parabola, Reed, Quart, Journ. Geol. Soc, vol. Iii, p. 435. 



Specific Characters. — Barrande's description of this species may be summarised 

 as follows : — Head parabolic, much elongated, with a flattened border prolonged at 

 the genal angles into spines almost as long as the glabella. Glabella, not 

 prominent, subclaviform ; front lobe inflated, occupying half the total length of the 

 glabella and twice as wide as the narrow somewhat depressed neck. Occipital ring- 

 broad, elevated, and projecting a little posteriorly. Axial furrows well marked. 

 Facial sutures with the anterior branch cutting the front margin a little outside 

 the eye, and the posterior branch cutting the middle of the posterior margin of 

 the head. Eyes of moderate size, opposite and as long as the neck of the glabella, 

 and situated a short distance from the axial furrows. Palpebral lobes rounded. 

 Surface of glabella ornamented with irregular concentric striae. 



Thorax of six segments; axis prominent, and about a fourth the width of the 

 thorax. Pleurae bent back at 60° in the middle of their length [with a strong- 

 median furrow on the inner half]; extremities rounded. 



Pygidium strongly arched from side to side [semi-elliptical in shape, about two 

 thirds as long as wide]; axis [prominent, tapering, not quite reaching posterior 

 margin] with 5 — 6 articulations. Lateral lobes with 2 — 4 faintly indicated 

 pleura? on each side. Border smooth, a little flattened, simple, slightly excavated 

 posteriorly. 



Remarks. — In addition to several detached head-shields and pygidia from 

 Thraive Glen in Mrs. Gray's collection, there is one perfect individual showing the 



