82 SYSTEMATIC AKRANGEMEXT 



ibid 600. Em. Mendez da Costa, Phil. Trans, vol. xlviii, p. 286. I. 



ToRRUBiA, Jpp. P- L. Hist. N. Espan. pp. 83, 13, n. 96, Com. iii, n. 4. 



GuETTARD, Mem. de V Acad. Poy. des Sei. torn, xv, PI. IX (VII), Fig. 2. Wilkens, 



Stralsund Magas. i, 4, Tab. I, Figs. A-2. Klein, Sjwc. Descr. j)etrpf. Gedan. Tab. 



XV, Fio-s. 5-7. J. J. Walch, Text zu Knorrs Abbild, d. Fersfein, vol. iii, p. 222, 



Tab. IX, Figs. 1-5. Beckmann, Nov. Conim. Soc. Peg. Göttingen, torn, iii, pp. 



101-2. Tril. fuberculatus. Brünnich, Nga. Sand. etc. i, 389. 1. Gehler, Progr. 



&r. 6. Fio-s. I-V. Blumenbach, Abbild. ?iaturk. Gegenst. i. Tab. L. Entom. 



paradoxus, Parkinson, Org. Bern, iii, PI. XVII, Figs. 11, 13, 14. Schlotheim, 



Petref. p. 39. 2. Wahlenberg, iV. A. f^«. viii, 31. 6. Ent. tuber culattis, Calymene 



Blumenbachii, Brongn. Or. foss. 11.1. PL I, Fig. 8, A-C. Schloth. Nachtr. ii, 



13. 1. and 33. 1. Dalm. Palcead. 35. 1, Tab. I, Figs. 2. 3. a-c. Payton, Tril. of 



Dudley, Fig, 14. Cal. Blumenb. Green, Mon. 28. KLÖDEN.Fe/'sA d. Mark Brand. 105. 



Harlan, Med. and Pliys. Research. 300. Murchison, Silur. Syst. ii, 653. PI. VII, 



Figs. 5-7. BuCKLAND, Bridg. Tr. p. 46. Figs. 1-3. Bronn, Lethaa, i, 110. 99, 



Tab. IX, Fig. 3. Hisinger, Leth. Suec. 10, Tab. I, Figs. 3-4. Boeck, Gaea. Norw. i, 



710. 16. Quenstedt, Weigmamis Archiv, 1835, i, 342. Emmr. Dissert. 39. 3. 



L. V. Buch, Beitr. z. Geog. Bussland, 47. Milne Edwards, Crust, iii, 318, 1. 



Cephalic shield lunate, the margin strongly reflexed but simple, thickened beneath ; 



o-labella indistinctly four-lobed, the first anterior lobe larger than the second, which is not 



so much separated from it as from the third ; the latter highly convex, but smaller than the 



fourth and posterior one. Eyes at the centre of the cheeks, not very prominent, placed on 



a line with the third lobe ; posterior margin of articulation much more narrow than the lobe 



preceding it. Thirteen rings in the body, which become successively smaller, without 



presenting any peculiarities. Caudal shield considerably smaller than the cephalic shield, 



the axis short, broad, seven-jointed, the two last joints indistinctly separated, the sides 



furnished with six radiating furrows, with intermediate ones along the whole length of the 



four central ones. The whole surface finely granulated in well-preserved fragments (var. 



pulchella, Dalman, /. c. Fig. 3), but more generally smooth, owing to the uppermost layer 



of the shell being absent. 



Remarks. — 1. I have compared all the authors quoted, as far as tliey were accessilile to me, and 

 conv-inced myself that they all treat of this species. The figures of Brongniart marked A, B, and of 

 Murchison, are the only ones sufficiently accurate ; in all the others the boundaries between tail and 

 body cannot be recognized with sufficient distinctness. Dalman's figure with ten body rings is 

 erroneous, and as erroneously copied by Hisinger. 



2. Zet/ius verrucosus of Pander, which M. v. Buch considers as belonging to this species, I have 

 preferred enumerating under Cal. Tristani ; his Z. uniplicatus (Beitrage z. Geogn. d. lluss. Reus. 138, 

 Tab. V, Fig. 7), with which the representation of Razoumowsky (Ann. Sc. Nat. viii, PL XXVIII, Fig. 4) 

 seems to correspond, has as little relation to this species. The glabella differs too much in both 

 figures to permit of their being referred to Calymene Blumenbachii, even supposing it to have been 

 imperfect iu the specimens that were examined by the authors cited. The species must therefore be 

 regarded as distinct. 



3. C. platijs, Green, Mon. 32, Milne Edw. Cr. I. c. 320. 4, I take to be a large specimen of C. 

 Blumenbachii, with perfect granulations. 



4. The numerous references above given sufficiently prove that this species is ^ddely extended ; 

 it i.s, however, only found in limestones,* and if its relation in this respect in England can be assumed 



* Not so in England. — Editors. 



