The Quarterly journal of the Geological Society of London . give a properdiagnosis. It is evidently a species of the subgenus Acaste, and not distantly allied to P. Brongniartii,a fossil from the Caradoc or Balarocks of Tyrone. I have two spe-cimens—one found by ProfessorHarkness, from which the figure istaken; another, smaller, is in thecabinet of Mr. H. Wyatt shows something the otherdoes not possess, and I shall de-scribe them together, as the figure is a sketch made up from bothspecimens. The whole form is broadly oval, much depressed, about half an inchwide, and about 1 inch l
The Quarterly journal of the Geological Society of London . give a properdiagnosis. It is evidently a species of the subgenus Acaste, and not distantly allied to P. Brongniartii,a fossil from the Caradoc or Balarocks of Tyrone. I have two spe-cimens—one found by ProfessorHarkness, from which the figure istaken; another, smaller, is in thecabinet of Mr. H. Wyatt shows something the otherdoes not possess, and I shall de-scribe them together, as the figure is a sketch made up from bothspecimens. The whole form is broadly oval, much depressed, about half an inchwide, and about 1 inch long; the head is semicircular, rather pointedin front, three-tenths of an inch long, and more than half an inchwide. The glabella is trapezoidal, the sides are nearly straight and widelydiverging from the base, which is only half as wide as the forehead-lobe. This is transverse, diamond-shaped, bluntly pointed, andangular in front, and divided from the three lateral lobes by a slightlysigmoid furrow, not deep, as in A. Brongniartii (the kindred species. 1866.] SALTEB NEW SPECIES OE TRILOBITES. 487 quoted above), but neatly impressed and nearly reaching to thecentre. The upper lateral lobes are triangular, the middle transverseand oval; the basal are linear, transverse, and nodose at the neck-furrow is strong, and the neck-segment not broader thanthe basal lobes. The cheeks (imperfect) appear triangular, and are gently convex fora large space before reaching the very large curved eyes. These havethe eye-lobe linear and distinctly marked out; and the lentiferoussurface, broad and much arched, reaches from the termination of theupper pair of furrows very nearly to the neck-furrow, which is ratherbroad and well defined. We do not yet know the free cheeks : theywere probably short and mucronate. The body-segments (seven are preserved in Professor Hark-nesss specimen) have a rather broad depressed axis, the rays beingobscurely nodular at the ends. The axial furrows are sli
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Keywords: ., bookcentury1800, bookdecade1840, booksubjectgeology, bookyear1845
