BEITISH FOSSILS. 



3 



olenus (sphierophthalmus) fl ag e l l i f e r. ? 



Plate YIII. Figs. 7, 8. 



Synonyms. Sphceroph. flagellifer, Angelin, PaL Suecica, pi. 26, 

 fig. 7. ? Salter, Mem. Geol. Surv., voL iii. ined. pi. 5, figs, 8, 9. 



The only difference I can see between the Tremadoc specimens 

 and the figure by Angelin is, that the glabella furrows in ours run 

 quite across, while Angelin gives them as only lateral. But as this 

 character of the complete transverse furrows seems to belong to 

 the whole of the SphceQ^ophthalmi, perhaps the Swedish artist has 

 not sufficiently represented it. The other characters of the sub- 

 genus (for it can, I think, only be so regarded) are the short and 

 wide transverse head, the cylindric glabella reaching the front 

 margin, and the very large curved head spines. 



Again, Eurycare, Angelin, which I regard as only Sphceroph- 

 thalmus, has a somewhat broader front, and wider and more para- 

 bolic glabella, thus leading from Sphcerophthalmus to the true 

 Oleni, of which 0. gihhosus may be taken as the type. The cha- 

 racters seem to me not to be absolute in any of these sub-genera, 

 and hence they may all, I think (and Barrande seems to be of the 

 same opinion), be conveniently retained in Olenus. 



Description. — Our specimens are so imperfect, that I do not 

 pretend to give a true diagnosis, nor do I feel quite sure I have 

 identified it rightty. 



The head is very transverse and has parallel edges. The glabella 

 is nearly square, and has ouly two pairs of furrows. The lower 

 reach far across, and appear quite complete in some specimens ; the 

 upper, not represented in our scanty figure, only lateral and short. 

 The ocular ridge is distinct and oblique. The margin very narrow. 

 The neck segment also narrow. The free cheeks rotund, the eye 

 large and prominent ; the spine seeming to start from the outer 

 edge above the angle. The thorax rings are strongly furrowed, their 

 axis moderately broad. 



The tail is entire, sub -triangular, with a conical axis, and furrowed 

 sides. Our specimen shows no trace of a spine such as Angelin 

 figures and describes. 



I think the species is a distinct one, but in the absence of more 

 complete materials, do not think it worth while to separate it from 

 its near ally. Our figure is necessarily imperfect, but might have 



