YAKUT AT FOSSILS 143 



specimen composed of seven successive loops. Of these the first is 

 > -shaped and considerably shorter and wider than the last three or 

 four. The cord decreases in average thickness from below upward, 

 the extreme measurements being 2.7 mm. and 2.0 mm. 



Distinguished from H. exacta by its more robust aspect and less 

 regular convolutions. From H. crassa Schafhautl, from the Eocene 

 of Switzerland, with which it agrees in size of the cord, it differs 

 in forming much shorter loops. 



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

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



Helminthoida abnormis sp. nov. 



Pl. XVI, fig. 4. 



In this species the windings of the cord, which often appears to be 

 crimpled and here and there knotted, and varies from 1.2 mm. to nearly 

 2.0 mm. in thickness, form very irregular and unequal loops. The 

 latter, however, can scarcely be called vagrant, since, despite their 

 irregularity, they seem to be confined to a space of nearly definite width. 



Distinguished from the preceding species by the irregular intertwin- 

 ing of the cord and its slightly knotted and crimpled character. The 

 same peculiarities separate it from all of Heer's species, among which 

 the usually much more delicate H. labyrinthica presents perhaps 

 more points of resemblance than any other known species. 



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



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



Helminthoida vaga sp. nov. 



Pl. XVII. 



In this form the cord, which averages about 2.2 mm. in diameter, 

 forms several large and more or less irregular loops or folds and then 

 becomes vagrant, the succeeding turns being without order and having, 

 apparently, no relation to the preceding loops. 



Fragments of this species appear to be abundant, but, on account 

 of the large size and straggling habit of growth, good and approxi- 

 mately entire specimens are likely to prove rare. Compared with 

 other species of the genus, and especially those found with it in Alaska, 

 it is distinguished at once by its large size and vagrant habit. Small 

 fragments might be confounded with Helminthopsis ? labyrinthica 

 Heer, but with more complete examples this is not likely to occur. 



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



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



