222 Parallelism of the Palceozoic Deposits 



C Fischeri, Eichw. — This species, characteristic of the lower 

 Silurian limestones of Russia and Sweden, is found at Knox- 

 ville, in Tennessee, at the base of the palaeozoic series. Prof. 

 Troost has a beautiful specimen of it. It is recognized by the 

 twenty-three articulations of which it is composed. We think 

 we might unite with it the Amphion pseudo-articidatus of Port- 

 lock, of the lower Silurian stage of Ireland. 



B. punctata, Briinn., sp. ; (C. variolaris, Brongn., not Murch.) 

 — This species has been found by Mr. Hall at Middleville, in the 

 Trenton limestone, and by Mr. Norwood at Madison, la., in the 

 lower layers of the cliff limestone, which correspond to the 

 Clinton group. We have seen it also at Springfield, Ohio, with 

 the Peniamerus oblongus, in the magnesian limestones, which 

 are undoubtedly parallel to the Clinton group. In England the 

 C. punctata is found both in the sandstones of Caradoc, and 

 in the schistose slates of Wenlock. In these same slates it is 

 found in the island of Gothland. In the islands of Dago and of 

 (Esel, as well as in those of Christiania, the C. punctata appears 

 to be found near the line of junction of the superior and inferior 

 stages of the Silurian system.* 



Illanus crassicauda, Wahl. sp. (Bumastzs trentonensis ? Em- 

 mons.) — We have seen only detached parts of this species, and 

 principally the post abdomen or pygidium. It belongs to the 

 most ancient beds. We recognize it upon the Black River, and 

 in the vicinity of Trenton, New York, in Pennsylvania, and at 

 Knox Wile, Tennessee, where it is associated with the C. Fischeri 

 This species occupies the same position in Europe, and belongs 

 exclusively to the inferior stage of the Silurian system in Eng- 

 land, in France, in Sweden, and in Russia. f 



Lichas laciniata, Wahl., or perhaps Lichas scabra, Beyrich. 

 It is very difficult to say to, which of these two species we should 

 refer the beautiful specimen found by Mr. Carly in the blue 

 limestones of Cincinnati. 



ppeara 



median? period seems an argument against the identity of the species in the two 

 positions, aside from other characters by which we regard it as positively distinct. 



J. H.l 



[I do not regard it as well ascertained that the species from the Trenton Iime- 

 atooe and the Clinton group of New York are identical. The species from the 

 Trenton limestone is given under the genus Ccraurus. in the first volume of the 

 Pater»ntolo|ry of New York. It is not a true Calymene, having the facial struc- 

 ture like Phacops, with eyes differing from either g ma. I have shown some 

 slight differences between Darapeetea and that of the Wenlock formation of Eng- 

 1 ; and there are other and more important differences between the one already 



described and that in the Clinton group— J. H ] 



. * EJJjf Bamaatis trentonensis of Emmons, 111*00* trentonensis, Pal. N. Y, vol. 

 1, p. 230, pi. 60, fig. 5, appears to be quite distinct from /. crassicauda, and is an 

 extremely rare species, while the latter is of frequent occurrence.— J. H.] 



