F. B. Cowper Reed — Some Wenlock Sjjecies of Lichas. 7 



Eemakks. — The head-shield shows considerable resemblance to that 

 of L. anglicus (Beyr.) ; but the latter may be distinguished by (1) the 

 more quadrato-oval shape of the anterior lateral bicomposite lobes of the 

 glabella, owing to the second lateral furrow meeting the first lateral 

 furrow at a right angle, (2) the greater size of the post-central lobe of 

 the glabella, (3) the small outward bend in the first lateral furrows in 

 the middle of the central lobe, (4) the absence of the basal portion of 

 the axal furrow, (5) the smaller lateral expansion of the anterior end 

 of the central lobe of the glabella, (6) the different shape of the free 

 cheek, and (7) the regular curve described by the posterior margin of 

 the head-shield. A comparison of Fletcher's figure (pi. xxvii bis, 

 fig. la) of L. anglicus plainly shows the points of difference. 



The glabella in L. anglicus is also generally of rather less width, 

 but is somewhat longer ; and the head-shield is not so bent down in 

 front, nor so swollen centrally. 



In the pygidium we see in L. liirsutus much resemblance to 

 L. Haiieri (Barr.),^ and the head-shield, with the exception of the 

 transverse post-central furrow, is likewise somewhat similar. The 

 peculiar laterally angulated outline of the posterior margin of the 

 head- shield and position of the spine on the free cheek is likewise 

 met with in X. Haueri and in other Bohemian species. 



The head-shield referred by Fletcher to Z. anglicus (pL xxvii, 

 figs. 1, la, 16), but mentioned as being of a slightly unusual form 

 (p. 236), should be attributed to L. Mrsutus, with which it agrees in 

 all essential features. 



Barrande {op. cit., p. 602) considered that Z. Mrsutus, Fletcher, 

 was identical with h\^ L. palmata (Barrande, op. cit., p. 599, pi. xxix, 

 figs. 1-13), but remarks that one of Fletcher's specimens (shown in 

 fig. 5, pi. xxvii, Q.J.G.S., 1850, vol. vi) represents a different form 

 to which the specific name L. Mrsutus must be restricted. Probably 

 Barrande meant fig. 7 instead of fig. 5, for the latter is attributed 

 by Fletcher to X. Bucldandi in his explanation of plate xxvii, 

 L. Mrsutus, Fletcher (excluding fig. 7, pi. xxvii), however, differs 

 from L. palmata in numerous points, the most important of which 

 are the absence of the well-defined middle glabellar and occipital 

 lobes, and in the pygidium the presence of only one strong axial 

 ring followed by several incomplete rows of tubercles. These 

 features are amply sufficient to separate it specifically. 



Lichas (Cortdocephalus) hirsutus, var. tuberculatus (var. nov.). 



(PI. I, Fig. 6.) 



Several specimens of a Lichas from the Wenlock Limestone or 

 Shale of Dudley show points of difference from the type-form of 

 Zi. liirsutus almost sufficient to constitute a distinct species. In the 

 head-shield the basal portion of the axal furrows is wanting, and the 

 fixed cheeks are completely confluent with the middle lateral portions 

 of the glabella; there is one conspicuously large tubercle on the 

 middle of the fixed cheek, and the eye-lobe projects laterally in 

 a very prominent manner ; the occipital ring also bears a large 

 ' Barrande: Syst. Sil. Bohem., vol. i, p. 604, pi. xxviii, figs. 38-44. 



