274 Dr. F. R. Cowper Reed — The genus Homalonotus. 



not all, of the species seem to show no glabellar lobes, though Salter* 

 describes furrows and lobes in his S. Brongniarti, Desl. 



In If. JDeslo?igchampsi, de Trom., Moriere^ describes the thoracic 

 pleurae as having a little angular projection at the point where they 

 begin to bend back, which fits into a notch in the preceding pleurse, 

 but it is not clear from Bigot's descriptions and figures (op. cit.) 

 if this structure is present in other species. 



The Gorranhaven specimens,^ which are most probably referable to 

 this group, are too poor for precise determination. 



Barrande * in his supplement figures and describes a perfect 

 individual of the Ordovician species^, bohemicus, Barr.,* from Stage 

 Dd 2, which Salter referred to the second subdivision of Brongniartia, 

 and this specimen is particularly interesting because it shows the 

 epistomal sutures starting at right angles from the points at which 

 the facial sutures bend inwards near the anterior margin and crossing 

 the pre-sutural band to pass to the inferior surface of the doublure. 

 We may, with much probability, assume that the closely allied other 

 species of this group have the structure of the front of the head- 

 shield and the behaviour of the sutures on a very similar plan. 



A considerable number of species seem to belong to this group, 

 and all those marked"^' come from the Gres de May or its undoubted 

 equivalents : — 



*H. serratus, de Trom. ?iJ. Viellardi, De Trom. 



*iT. Bonnisenti, Moriere. ?iJ. draboviensis, Novak'' (Bohemia). 



*H. incertus, Bigot. ^H. bohemicus, Barr. (Bohemia). 



*j?. Brongniarti, Desl. H. Brongniarti,T)e Yexn.non Desl.^ 

 *il. Vicaryi, Salt. (from Sierra Morena). 



*H. Deslongcliam-psi, de Trom. H. biserratus. Reed, sp. nov., 

 *H. Morierei, Bigot. Shropshire. 



*H. besnevillensis, Bigot. H. [Neseziretus] quadratus (Hicks), 

 H. Barroisi, Lebesc.^ Eamsey Is. 



5. Kcenigia, Salter, 1865. 

 The type of Salter's section Kmnigia is H. ITnighti, Konig,^ of the 

 Upper Ludlow Beds of England and Sweden, which Konig chose as 

 the type of his genus Komalonotus . The latter name is now generally 

 employed in a more comprehensive manner, the characters' of 

 S. Knighti being extremely uncommon and scarcely representative 

 of the whole assemblage of species. The name Kcenigia therefore 

 seems desirably applicable in this restricted sense to the group of forms 

 resembling S. Knighti. Salter included his H. ludensis in Kmnigia, 



^ Salter, Quart. Journ. Geol. Soc, vol. xx, p. 290, pi. xv, fig. 1, 1864. 



" Morik'e, Bull. Soc. Linn. Normandie, ser. Ill, vol. viii, p. 383, pis. i, ii, 

 1884. 



•* Collins, Trans. Eoy. Geol. Soc. Cornwall, 1893, p. 53 (reprint). 



■* Barrande, Syst. Silur. Boheme, Suppl. 1, p. 37, pi. i, fig. 6. 



^ Barrande, Syst. Silur. Boheme, vol. i, p. 580, pi. xxxiv, figs. 40-2. 



•^ Lebesconte, Bull. Soc. Geol. France, ser. in, vol. xiv, p. 801, pi. xxxvi,. 

 figs. 12, 13, 1857. 



^ Novak, Bohm. Trilob., i (Beitr. Palseont. Oest. Ung., Bd. iii, 1881), p. 27, 

 t. viii, figs. %a-c. 



* De Verneuil, Bull. Soc. Geol. France, ser. ill, vol. xii, p. 971, pi. xxiii, 

 fig. la, 1855. 



^ Konig, Icones Sectiles, 1825, pi. vii, fig. 85. 



