TRILOBITES OF THE UPPER SILURIAN ROCKS. 



655 



Steininger has not published a specific name, but I learn from M. de Verneuil that he has 



recently assigned to the fossil the above descriptive term. 

 Asaphus Cawdori, (n.s.), f. 9. 

 Asaphus suhcaudatus, (n.s.), f. 10. 



These post-abdominal terminations of trilobites differ from any published species with which 



I am acquainted, and are probably portions of an Asaphus. I have named No. 9. after the 



Noble Earl who discovered it. 



Loc. Fresh-water East, South Pembroke, where they were both found in Upper Silurian 

 Rocks by the Earl of Cawdor. 



The species No. 10. has been also observed by Mr, Lewis in the Aymestry limestone near 

 Ludlow. 



N.B. Other Asaphi which occur in the Wenlock, Caradoc and Llandeilo formations, are 

 described in the subsequent pages. 



TRILOBITES OF THE UPPER SILURIAN ROCKS {continued), 



PLATE XIV. 



Calymene variolaris, i. 1. Brong. (var. ?) 



Spec. Char. — Clypeo rotundato, lobis inflatis v aide tuber culatis, angulis externo-posticis in 

 mucronem productis (Brongn.). 



The prominent distinction of this species consists in the highly ornamented pear-shaped 

 central lobe of the head with a swelling front. 



M. Brongniart also remarks, " that the numerous small tubercles with which the animal is 

 covered have a small aperture near their summit, similar to the tubercles to which the spines 

 of Cidaris are attached," a distinction which I have never observed. Can the remarkable pro- 

 longation of the lateral edges of the buckler, given in the figure of Brongniart, PI. 1. f. 3 A. } 

 have been obliterated in our specimen, or is the latter a variety ? 



Loc. Wenloch Edge and Dudley. The Calymene variolaris is not very common. It is (as 

 far as I know) peculiar to the Wenlock formation. 



The specimen figured is from the cabinet of Mrs. Downing. 

 Calymene macrophthalma (Brong.), f. 2. Brongn. PI. 1. f. 5 A, B and C. 



Head round and plain in central division. Eyes very large and protuberant, occupying the 

 greater portion of the sides or cheeks and composed of many lenses. The back, M. Bron- 

 gniart remarks, has 12 or 13 articulations and is neatly separated from the short pointed tail. 

 Loc. Wenlock and Dudley, but, like the C. variolaris, less frequently than the Asaphus caw 



datus and Calymene Blumenbachii. 

 Calymene? Downingice (n.s.), f. 3. Buckl. Bridgw. Treat. PL 46. f. 5. 



Head ovate-acuminate, central part divided on each side by 3 transverse furrows into tubercles. 

 Eyes rather smaller than in C. macrophthalma, but similarly ornamented. 



I have separated the Calymene macrophthalma, Brong., into two species, believing that his 

 figure, PL 1. f. 4 B., is our common, large-eyed species, and that his f. 4 A. of the same Plate, 

 judging from the ovate-acuminate head and the tubercles on the forehead, is our C. Downingice. 

 The last-mentioned species is infinitely rarer than that to which I would restrict the name of 

 macrophthalma. That species is at once recognized by its bald, plain, rounded head, as is 



4 o 2 



