142 BRITISH PALAZOZOIC FOSSILS. [CRusracea. 
Trinopus TARDUS? (Bar. Sp.) Pl. 1. E. fig. 9. 
Syn.—Battus tardus Barrande. <Arthrorachis tarda Hawle and Corda. Agnostus trinodus Salt. 
Mem. Geol. Surv. Vol. II. t. 8. fig. 11. (omit the ref. to M°Coy). 
Sp. Ch.—Cephalic shield truncato-orbicular, about one-fifth wider than long; glabella not quite two 
thirds the length of the head, very broad, ovate, nearly as wide as long, convex, defined by a very deep 
furrow; cheek-piece of equal width all round, about one-third less wide than the glabella, convex, a wide 
hollow separates the cheek from the narrow external margin, the hollow and margin taken together about 
equalling the cheeks in width. Length of head two lines. 
We have only the head of this species which seems to agree exactly with the Bohemian form noticed ; 
the tail apparently of the same species is figured from a Wexford specimen by Mr Salter in the ‘“‘ Memoirs of 
the Geol. Survey” as the original variety of my 7. agnostiformis; this reference however (as any one may 
see by referring to my original description and figure,) belongs rather to his A. trinodus 8 conveaus. The 
segmental furrows of the pygidium are not indicated in Mr Salter’s notice. 
Position and Locality—One specimen in the Limestone of Rhiwlas, N. of Bala Lake, Merionethshire. 
Explanation of Figures.—Pl. 1. E. fig. 9. Head, natural size, and magnified six diameters: the dotted 
line indicates the completion of the broken margin. 
Genus. DIPLORHINA (Hale and Corda). 
Gen. Char.—Cephalie shield rotundato-quadrate ; glabella subcylindrical, rounded in front, divided near 
the middle by a strong transverse sulcus, and having a small rotundato-trigonal lobe on each side of the 
base ; checks horse-shoe shaped, entirely surrounding the glabella; outer margin narrow ; ¢horaa of two rings, 
axis about four times wider than the pleuree, which are obtuse, and divided by a diagonal pleural furrow ; 
pygidium very obscurely rotundato-pentagonal, longer than wide, axis convex, mitre-shaped, middle of the 
sides concave, pointed posteriorly, bordered behind and at the sides by uniformly continuous side lobes ; 
outer margin rather wide, smooth, 
DipLoruina tTRiPLICATA (Hale and Corda)? Pl. 1. E. fig. 11. 
Syn. and Ref.—Agnostus pisiformis Murch. Sil. Syst. t. 25. f. 6a@ (not of Brong.) 
Sp. Ch—Head rotundato-quadrate, length and width almost equal; cheek-piece slightly narrower than 
the glabella, and a little wider near the middle of the glabella than in front, moderately convex, divided 
in front by three radiating sulci, one medial and one on each side about half way between that and the 
medial transverse sulci of the glabella; glabella subcylindrical, rounded in front, slightly concave at the 
middle of the sides, divided slightly in front of the middle by a strong transverse sulcus, the anterior portion 
evenly convex, posterior portion more prominent, obtusely carimate along the middle; a small obtusely 
trigonal segmental lobe on each side of the base of the glabella. Surface minutely shagreened. Length and 
width each about one and a half lines. 
As Hawle and Corda have not figured their species, I subjoin, in a note*, that part of their descrip- 
tion applying to the head. 
Position and Locality—Rare in the black shale of Pen Cerrig, three miles N. of Builth. 
Explanation of Figure-—P\. 1. E. fig. 11. Head, natural size, and magnified six diameters. 
* “Kopf flach gewélbt, vorne gerundet, fast parallelopipedisch; breit gerandet, Rand flach, Randfurche seicht. 
Wangenstiick hufeisenformig und iiberall gleich breit, Vor den Vorderlappen der Glabella mit drei kurzen, nach yorne 
gerichteten Falten geziert. Dorsalfurchen tief. Vorderlappen trapezoidisch, mit der breiten Basis an den etwas nach 
Vorn ausgeschweiften Mittellappen der Glabella stossend; letzterer ist nahe am Vordern Ausschnitt mit einem kurzen 
scharfkieligen Buckel geziert, zur Seite und nach hinten ausgeschweift ausgeschnitten. Basilarlappen klein, dreieckig.” 
Prod. Monog. der béhm. Tril. p. 47. 
