﻿CALYMENE. 



93 



C. Blumenbachii, Auctorum. PI. VIII, figs. 7 — 16. PI. IX, figs. 1, 2. 



Lyttelton. Phil. Trans., vol. xlvi, pis. i, ii, p. 598, 1750. 



Mortimer. Ib. p. 600. Mendez da Costa, ib., vol. xlviii, p. 296, 1753; also 



Guettard, Wilckens, Klein, Walch, Beckmann, &c, 1757 to 1773. 

 C. platys, Green's Monograph; cast No. 4, 5, (not C. Blumenbachii, id.) 1832. 

 Tkilobites tuberculatus, Brunnich. Nye Samml., &c., i, 389, 1 ; 1781. 



— — Blumenbach. Abbild. Naturb. Gegenst., i, t. 50 ; 1810. 



. Entomolithes paradoxus, Parkinson. Org. rem., Ill, pi. xvii, figs. 11, 13, 14; 1811. 

 — tuberculatus, Wahlenberg. Nov. Act. Ups., viii, 31,6; 1821. 



Calymene Blumenbachii, Brongniart. Crust, foss., ii, 1, pi. i, fig. 1 a — c ; 1822. 



— — Batman. Palsead. 35, 1, tab. i, figs. 2 — 3 a — c ; 1826. 



— — Payton. Trilob. of Dudley, fig. 14 (plate only) 1827. 



— — Murchison. Sil. Syst., pi. vii, figs. 6, 7 (not fig. 5) 1837. 



— var. Niagarensis, Hall. Pal. N. York, vol. ii, p. 307, pi. lxvii, figs. 1 1, ] 2; 1852. 

 Calymene Niagarensis, Hall. Geol. Report 4th district, p. 101, fig. 3 ; 1843. 



— subdiademata, M'Coy. Pal. Foss. Woodw. Mus., pi. i f, fig. 9 only ; 1851. 



— spectabilis, Anyelin. Palseont. Suecica, t 19. f. 5 ; 1852. 



C. magna 3 — 5 uncialis, elongata, valde convexa, — per totum tuberculosa. Caput gla- 

 bella magna longd, utrinque triloba, marginem frontalem compressum crassum haud produc- 

 tum attingente ; gents declivibus, vix glabella- latioribus. Thorax axe quam pleuris lato, 

 convexo fere gibbo ; pleuris dejlexis nec planis, fulcro approximafo, antice adtertiam, postice 

 ad quintam partem latitudinis posito. Cauda angusta, subtrigona, axe gibbo, lateribus 

 declivibus b-costatis, coslis omnibus bifidis, sulcis profundus. 



It is necessary to be diffuse in the specific character ; for in this genus it is only by 

 contrasted differences of proportion that we are able to distinguish the species. C. Blu- 

 menbachii, like all common Trilobites, has a considerable range of variation ; but the 

 greatly extended large glabella is after all the best character of the species. It occupies 

 fully a third of the head in width, and is so long as to touch the thickened front margin, 

 which is neither produced nor much reflexed. In this all the specimens agree, while 

 they differ in points of mere proportion. The glabella is sometimes a little wider, espe- 

 cially at the base j sometimes less convex, but always more prominent than the cheeks, 

 and even overtopping the eye-tubercles. The tail varies in width, but is always trigonal 

 with deflexed strongly ribbed sides ; and the pleurae, always strongly decurved, are some- 

 times flatter, and sometimes very convex, i. e., curved very strongly down, as in our 

 figure 15. 



The species being so common, it is only necessary to describe the points relied on for 

 its distinction from others ; for the Dudley fossil has been much confused with kindred 

 forms, and these differ sufficiently from it when closely examined. 



C. Blumenbachii is the largest of the genus ; our fine central specimen, the one figured in 



