PERMIAN FOSSILS FROM DURHAM. 289 



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. V\. XII. fig. 8. 



Loxonema Roessleri, Geuiitz, Jahreshericht Wetter auisch. 

 Gesell. 1850-51 ; Schauroth, Zeitschr. deutsch. geol. Gesell. 

 1854, vi. 538. i^Z. 21./^. 9. 



In 1853 I oLtaincd a very fine specimen of a ribbed Chemnitzia 

 at Hnmbleton Quarry, which agrees very well with the Loxonema 

 Eoessleri, Geinitz, as figured by Baron Schauroth in the " Zeit- 

 schrift d. dentsch. 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 " Tran- 

 sactions 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. ''f 

 This is probably the same as the one now before us ; and is un- 

 doubtedly distinct from Loxonema Swedenborr/iana, King (Mono- 

 graph Perm. Foss jd. 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 per- 

 fect 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 num- 

 bered eight or nine) are somewhat convex, rather tumid behind, 

 ^vith the suture deep ; they are covered with thick, close-set, 

 transverse ribs, giving to the shell a fluted a2)pearance ; 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 



* Sep Xotc 1, at the end of this Paper. 



t Transact Tyneside Nat. Field CIuIj, vol. -ill. 



