149 



vwords, there are .a. number of transitional stages in this respect. Thus the 

 -writer is not inclined to accept the proposal of Reed. Gurich has already 

 iremarked that these are the characteristics of the species Spirifer vcr.neitili 

 \{j==Sp. disjunctns), but not those of any particular variety. 



Geological Age : — " Seine Hauptverbreitung fallt in das untere Ober- 

 »devon. Bisweilen geht er bis zu den carbonishen Grenzschichten z. B. in 

 ,Armenien." (LoEvyE : — op. cit., p. 43;) 



II. Spirifdr disjunctus var. sub-archiaci Martelli. 



PI. XXIII., , Figs. 23 and 24; PI. XXIV., Fig. i. 



1853. Spirifer arc]iiaci,'^c\mv^: — loc. cit. • ■ 



1853. Spirifer disjunctus, Davit^son : — loc. cit. 



1864. Spirifer disjunctus Davidson : — loc. cit. 



1883. Spirifer verncuili, Ravser : — loc. cit. 



1883. Spilifer officinalis, Kayser (Pars).: — loc. cit., figs. 3a-b. 



1884. Spilifer nrcJiiaci, Ts,c\\^?imNZCYi^\N : — loc. cit. 

 1887. Cyrtia niurcJdsoniana, Tschernvschew : — loc. cit. 



1894. Spilifer vernaiili, Gosselet (pars) : — op. cit., figs. 30, 38, 39, etc. 



1902. Spilifer verneuili \2lX. suh-arcJdaei, Martelli : — loc. cit. 



1902. Spirifer verneuili \diX. lonsdalii, Martelli (pars): — op. cit., pi. 

 XIV., fig. 8. 



1902. Spirifer disjunctus, Hudleston (pars) : — op. cit., figs, 11 and 12. 



1912. Spirifer disjunctus Ya.r. yininanensis, Mansuv : — loc, cit. 



1913. Spirifer disjunctus var. sub-archiaci, Pellizzari : — loc cit. 



Shell somewhat swollen, but in no way globular : the ventral valve far 

 ; more convex than the dorsal. The hinge-line is almost equal to or a little 

 shorter than the maximum width of the shell. Ventral valve with a large 

 • cardinal area, which is hardly pointed out over the beak. The area is dis- 

 tinctly triangular and concave, with a delthyrium of an equilaterally triangular 

 rform. The beak is rather obtuse and upright. At the tip of the beak begins 

 .a median sinual depression which is either. triangular (or V-shaped) or some- 



