144 ALASKA GEOLOGY 



Genus Helminthopsis Heer. 

 Helminthopsis magna Heer. 



Pl. XXI, figs. I, 2. 



Helminthopsis magna HEER, Flora Foss. Helvetia, p. 116, taf. XLVII, figs. 

 i, 2, 1877. 



Fucoid originally cylindrical and tubular, now flattened, several feet 

 in length, 12 mm. to 25 mm. in width, the edges thickened, forming 

 serpentine convolutions over the surface of slabs of arenaceous slate. 

 The larger of the two specimens before us exhibits distinct transverse 

 wrinkles, while on portions of the smaller specimen longitudinal lines 

 as well as obscure transverse undulations may be discerned. 



Heer described the surface of his specimens as smooth, and the 

 thickened margins of the compressed tubes are heavier in his figures 

 than in the Alaska specimens under consideration. Despite these dif- 

 ferences we believe the latter belong, if not strictly to the same species, 

 at least to one so near the Swiss Upper Liassic form that we are not at 

 present warranted in separating it. Possibly the differences are due to 

 faulty observation or to the less favorable preservation of Heer's origi- 

 nals. However, this point may turn out, it is certain his figures look 

 very much like our specimens. 



Locality. Pogibshi Island opposite the village of Kadiak ( ? also 

 Woody Island), Alaska. 



Collector. G. K. Gilbert. 



Helminthopsis? labyrinthica Heer. 



Pl. XX, figS. 2, 3. 



Helminthopsis labyrinthica HEER, Flora Foss. Helvetiae, taf. XLVII, figs. 3-5, 

 1877- 



This fossil consists of simple, smooth, cylindrical, stony cords 1.8 

 mm. to 2.5 mm. in thickness, meandering, in the cases before us, 

 over the surface of arenaceous slates. The stems are usually thrown 

 into more or less irregular and unequal loops, often horseshoe-shaped, 

 and sometimes recalling the more regularly formed loops of Helmin- 

 thoida. 



The Alaskan specimens under consideration agree so closely with 

 Heer's figures of the Swiss Upper Liassic specimens upon which he 

 founded the species H. labyrinthica that we can not doubt they belong 

 to the same species. As to the propriety of referring the species to 

 Helminthopsis, we are inclined to differ from the able author of the 

 Flora Fossilis Helvetiae. Considering H. magna as the type of the 

 genus, Helminthopsis should be restricted to species having the con- 



