216 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jail. 21, 



The specimen with the carapace (figs. 1-3) is one-eighth of an 

 inch long. The largest of those with the body-segments only (fig. 4) 

 is nearly half an inch in length . 



2. Chemnitzia Roessleri, Geinitz, sp. PI. VII, fig. 8. 



Loxonema Roessleri, Geinitz, Jahresbericht Wetterauisch. GeselL 

 1850-51 ; Schauroth, Zeitschr. deutsch. geol. GeselL 1854, vol. vi. 

 p. 538. pi. 21. fig. 9. 



In 1853 I obtained a very fine specimen of a ribbed Chem- 

 nitzia at Humbleton Quarry, which agrees very well with the Loxo- 

 nema Roessleri, Geinitz, as figured by Baron Schauroth in the 

 ' Zeitschrift d. deutsch. geol. Ges.' 1854, vol. vi. p. 538. pi. 21. fig. 9. 

 A notice of the occurrence of this interesting fossil was given, to- 

 gether with that of the above-described Crustacean, in the Transac- 

 tions of the Tyneside Naturalists' Field Club, vol. ii. p. 333. 



The first account of a ribbed Chemnitzia from the Permian rocks 

 is found in Mr. Howse's 'Catalogue of Permian Fossils *.' This is 

 probably the same as the one now before us ; and is undoubtedly 

 distinct from Loxonema Swedenborgiana, King (Monograph Perm. 

 Foss. p. 210), though Baron Schauroth is disposed to consider the 

 two identical. The size, however, is sufficient to distinguish them. 



I have given a figure of this specimen (fig. 8), as Schauroth's 

 figure is from a very imperfect individual. My specimen is perfect 

 with the exception of two or three of the apical whorls ; the six 

 whorls that remain give a very good idea of the species. This shell 

 is long and slender, tapering gently to an apparently very fine point ; 

 the whorls (which, when entire, probably numbered eight or nine) 

 are somewhat convex, rather tumid behind, with the suture deep ; 

 they are covered with thick, close-set, transverse ribs, giving to the 

 shell a fluted appearance ; the large whorls have about eighteen ribs 

 each, and are finely striated on the under surface. The pillar-lip, 

 as far as can be observed, is straight, but the greater portion of the 

 aperture is hidden in the matrix. 



There is little doubt that this is a true Chemnitzia : the form of 

 the shell, the character of the whorls with their ribs, the deep suture, 

 and straight columella, pronounce it to belong to this genus. The 

 whole habit of the shell, too, is very similar to that of Chemnitzia. 



3. Chiton Howseanus, sp. nov. PL VII. figs. 9-13. 



Three plates of a Chiton have occurred at Tunstall Hill, which, on 

 a careful examination, appear to be distinct from Chiton Loftusianus, 

 King (Monog. Perm. Foss. p. 202. pi. 16. figs. 9-14), of which I 

 have a full series. 



Of the new species two of the plates are intermediate (figs. 10, 11, 

 12), and one anterior (fig. 13). The former plates are not much 

 compressed ; they are wide and obtusely angulated, not much pointed 



* Transact. Tyneside Nat. Field Club, vol. i. p. 241. 



