YAKUTAT FOSSILS 145 



voluted cylindrical stem originally hollow. H. labyrinthica, on the 

 contrary, was almost certainly solid. What to do with the latter we 

 are not prepared to say, although we have provisionally referred 

 what we believe is a congeneric species to Helminthoida under the 

 name of H. vaga. So far as we can see the latter is distinguished 

 from H. labyrinthlca only by its much longer loops and generally 

 looser habit of growth. 



Locality. Pogibshi Island, opposite the village of Kadiak, Alaska. 



Collectors. G. K. Gilbert, B. K. Emerson, Charles Palache. 



Genus Myelophycus gen. nov. 

 {Miinsteria, part, Fischer-Ooster.) 



As interpreted these supposed marine plants were simple, curved, 

 subcylindrical or claviform masses, consisting of an outer laminated 

 and superficially granulose integument and an inner pith-like portion 

 made up of a succession of conical cups set one into the other. 



Besides the type species next described we know of only one other 

 form that we would refer to this genus. This was figured in 1858 by 

 Fischer-Ooster in his paper entitled Die fossilen Fucoiden der 

 Schweizer-Alpen (pi. xvi, fig. 5), and referred by him to Munsteria 

 hcessii Sternberg. Comparing this figure with all others at hand of 

 Sternberg's species, we find that it is clearly distinct, the M. hcessii 

 of other authors being without the granulose external integument. 

 This outer integument and the invaginated cones of the inner portion 

 distinguish the proposed genus from Munsteria, Keckia, Ceratophy- 

 cus, Caulinites and other genera having a transversely wrinkled surface. 



Myelophycus curvatum sp. nov. 



Pl. XIII, fig. 2. 



The originally cylindrical or club-shaped masses upon which this 

 species is founded are now greatly compressed and cover most of one 

 surface of a slightly arenaceous slab of slate about 8 inches wide and 

 between 12 and 13 inches long. They are from 10 cm. to 15 cm. 

 long, strongly curved, and from 2 cm. to 4 cm. wide, the latter di- 

 mension being at one of the extremities, which as a rule is more or less 

 expanded. The average width may be set down at about 3 cm. 

 When the outer integument, which is thick, laminated and superfici- 

 ally rather coarsely granulose, is worn away, the invaginated cones of 

 the inner structure, which takes up about half the width of the entire 

 fossil, are exposed. When the wearing has not materially affected 

 these, then only their straight or accidentally curved edges are seen, 



