ILL^ENUS BALCLATCHIBNSIS. L63 



possess ;i broacj axis bearing on each ring a pair of circular gland-like pits 

 resembling those found on the third ring of C. binodosa, Salter. 1 The pleura' are 

 short and imperfect. Probably these segments belong to C. rediviva, as they agree 

 in point of size. 



Cyclopyge cf. gigantea (Barrande). Plate XX, fig. 5. 



One pygidium from Whiteliouse Hay amongst Mrs. dray's recently collet-ted 

 material belongs undoubtedly to the genus Cyclopyge, but does not seem to be 

 referable either to G. armata or 0. rediviva. It has a transversely semicircular 

 shape, and a well-marked, raised, rounded border ; the axis is conical, pointed, and 

 well defined by the axial furrows, which extend with nearly uniform strength to its 

 tip, and converge at an angle of about 45°; the axis is completely ringed to its tip 

 by five or six annulations, of which the first three are strongly marked; the lateral 

 lobes are very slightly convex and show faint traces of 3 — 4 pleurae, but these are 

 very indistinct. The first lateral furrow is, however, strong. 



The pygidium figured by Barrande as belonging to a young individual of 0. 

 gigantea (Barr.) 3 has a somewhat similar long pointed conical axis, with traces of 

 several rings upon it and of faint pleurae on the lateral lobes. In 0. yrisca 

 (Barr.) 3 the axis is too short and blunt, but has 3 — 4 rings well marked on it. 

 Dimensions. — 



Length of pygidium .... 7'0 nun. 



„ of axis ..... 5 - ,, 



Width of pygidium . . . ca. 1 4'0 „ 



,, of axis at front end . . . 4 - 25 „ 



Genus ILLiENUS, Dalman. 

 Illaenus balclatchiensis, Reed?. Plate XX, tig. 11. 



1904. Illsenus balclatchiensis, Reed, supra, p. 50, pi. viii, tigs. 12 — 10. 



There is now available one good hypostoine from Balclatchie which may be 

 probably attributed to the species 1. balclatchiensis. It is transverse in shape, 

 being nearly twice as wide as long. The anterior v^l^c is nearly straight ; the 

 lateral wings form very broad, flattened, rounded lobes, slightly upturned behind ; 



1 Salter, 'Mem. Geol. Surv.,' dec. xi. no. iv (1804), pi. iv, figs. 1 — 0. 

 - Barrande, ' Syst. Silur. Boheme,' suppl. vol. i, p. 00, pi. i, fig. 5. 

 :i Ibid., p. 03, pi. v, fig. 2. 



