I916. No. 10. THE LOWER CAMBRIAN HOLMIA FAUNA. 49 



With the Lower Cambrian Stremwlla forms in Scandinavia there 

 appear the oldest representatives of the genus Ellipsoccphaliis. 



Unfortunatelv we have a knowledge only of cranidiums (without the 

 free cheeks) and the thoracic segments; but taking everything into considera- 

 tion the forms may be considered to be intermediate between Strcmtclla 

 and the Middle Cambrian species of Ellipsoccpholns. They are often so 

 similar to Streuuella, that in consequence we might be inclined to refer 

 them to that genus. The occipital ring is always very distinct, often sharply 

 limited, and the lateral furrows of the glabella are often distinct like 

 those of Ellipsocephalus Xordetiskjöldi Lnrs. ; but the more parallel limits 

 of the glabella, which is often slightly pointed to an angle, clearly point 

 towards typical Middle Cambrian species of Ellipsocephahis. 



The oldest Middle Cambrian forms also strengthen this view, for in 

 several respects they are situated between the Lower Cambrian species 

 and the most specialised species, Ellipsocephalus Hoffi Schl., which is 

 the type of the genus. 



In the North American Protoleiiits Fauna in New Brunswick, which 

 is older than any of the known Scandinavian Middle Cambrian faunae, we 

 find two such forms. Ellipsocfplialns galeafiis Matthew, and grandis 

 Matthew ^ 



These two forms strongly remind one of El. Xordetiskjöldi Lnrs., 

 with their distinct occipital ring and distinct furrows on the glabella, but 

 the latter is more strongly- extended anteriorly and thus more similar to 

 El. Hoffi Schl. The segments, too, appear to approach that form, appa- 

 rentl}' showing a complete reduction of the rudimentary spines. 



Ellipsoceplialus vetustiis Pompeckj - too, from the quartzic conglomerate 

 sandstones and gray-wacke sandstones of Kamennâ hurka in the neighbour- 

 hood of Tejrovic in Bohemia, lies very close to our Lower Cambrian forms. 



The Scandinavian Middle Cambrian species, of which our more exten- 

 sive knowledge is due to the researches of Linnarsson, in several respects 

 appears to form an interesting intermediate stage between our Lower Cam- 

 brian forms and the type of the family Ellipsocephalus Hoffi Schl. 



At the present time we are acquainted with 3 species from Sweden, 

 Ellipsocephalus polytonuts Lnrs. from the Paradoxides Ølandicus zone in 

 Øland, El. nniticus Ang. and El. ^rauulatus Lnrs. from the Paradoxides 



^ Matthew, Illustrations of the Fauna of the St, John Group. (Transact. Roy. Soc. 



Canada, Vol. XI, 1897. pp. 103—105, pi. XVII, figs. 6 — 7). 

 - J. F. Pompeckj. Die Fauna des Cambricum von Tejrovic und Skrej in Böhmen ijahrb. 



d. k. k. Geolog. Reichsanst. Bd. 45, 1895, P^g- 552, pi. XVII, fig. 3.) 



Vid.-Selsk. Skritter. I. M -N. Kl. 191 6. No. 10. 4 



