43 mr. E. s. cobbold on two species or [March 191 3,. 



The two free cheeks which may he referred with little hesi- 

 tation to the species (figs. 1 & 5) belong to larger individuals. The 

 area is decidedly wide, particularly near the posterior margin, but 

 in both specimens it is crushed to a mosaic, and its original form 

 cannot be accurately determined ; the marginal fold is fairly convex, 

 and is continued to form a long and sharp spine, the length of 

 which is about equal to that of the cheek itself. The upper surface 

 of the fold shows a few raised lines, which creep over the margin 

 on to the doublure, where they become more plentiful. In Salter's 

 description the margin is said to be smooth. On specimen Is'o. 2422 

 (PL IV, fig. 1) a few similar lines are to be seen on the under side 

 to the area of the cheek, where they run in a direction sub-parallel 

 of the curve of the eye. 



Locality and horizon. — Neve's Castle (Shropshire), near the- 

 southern end of the Wrekin. Middle Cambrian. 



Conclusions. 



The rock-specimens, in which the two species of Paradoxides are 

 found, contain a few other fossils, among which the following have 

 been recognized : — 



Agnostus sp., cf. A. fallax Einnarsson. Agraulos sp., cf. A. quadrangularh 



Aqnostus sp., of tbe type of A. eieer 



'Tullberg. 

 Ptychoparia (Liostracus) sp., compare 



(Whitfield). 

 Hyolitlms sp. 

 Hyolithellus sp., cf. H. fistula Hall. 



tbe forms from Ooinley. [ Acrotreta sp. 



Until further specimens of the smaller trilobites are forthcoming, 

 it is impossible to say definitely which horizon of the Middle 

 Cambrian is represented. 



Paradoxides Jiicksi, the two above-named species of Agnostus. 

 and a similar form of Liostracus are found in the Tessini Zone of 

 Scandinavia. 



For previously-published references to the Neve's Castle locality 

 see : — 



1877. C Callaway. Q. J. G S. vol. xxxiii, p. 662. 



1894. C. Lapworth & W. W. Watts, Proc. Geol. Assoc, vol. xiii, p. 310. 



1910. C. Lapworth & W. W. Watts, Geol. Assoc. Jubilee vol. pt. 4, 



p. 750. 



1911. E. S. Cobbold, Q. J. G. S. vol. lxvii, p. 283. 



EXPLANATION OF PLATE IV. 



[All figures are of the natural size, except 2c & 2d. The letters and 

 numbers in square brackets are those attached to the specimens.] 



Paradoxides Jiicksi Salter. (See p. 47.) 



Fig. 1. Free cheek [R.R. 2422]. 



2. Nearly complete cranidium, somewhat flattened [R.R. 2376] : a, seen 



from above; I), seen from the side; c, enlargement of the median 

 part of the occipital ring ; d, enlargement of part of a fixed cheek. 



3. Incomplete cranidium, somewhat flattened [R.R. 2394]. 



4. Nearly complete cranidium of immature individual [R.R. 2380] . 



5. Free cheek of a comparatively large individual, much crushed. 



[R.R. 2422]. 



