344 



BULLETIN 11, UNITED STATES NATIONAL MUSEUM. 



Fig. 219.— Dianulites apiculatus. a to d, fotje 



VIEWS OF EICHWALD'S .TYPE OF CHjETETES 



apiculatus; e, celluliferous surface en- 

 larged. (After Eichwald.) 



DIANULITES APICULATUS (Eichwald). 



Plate 2, figs. 7, 8; text fig. 219. 



Millepora apiculata Eichwald, Inter ingrica, 1825, p. 21. 



Orbitulites apiculatus Eichwald, Zool. spec, vol. 1, 1829, p. 150, pi. 2, fig. 3. 



Chxtetes apiculatus Eichwald, Lethsea Rossica, vol. 1, 1860, p. 479, pi. 28, figs. 



1 a-d. 

 Dianulites apiculatus Dybowski, Die Chaetetiden der Ostbaltischen Silur-Form., 



1877, p. 32, pi. 1, figs. 7, 8. 



Eichwald' s figures and description of Clisetetes apiculatus are of 

 practically no value in distinguishing it from the numerous other 



massive Russian bryozoans. Dy- 

 bowski's treatment of the species 

 is but little better. My guess 

 regarding the species is that it is 

 founded upon small examples of 

 Dianulites petropolitana, or some 

 other massive bryozoan with 

 the base covered by a layer of 

 the smaller, thick-walled, closely 

 tabulated mesopore-like cells. 

 Occurrence. — Dybowski cites Erras, Duboviki, Pulkowa, and 

 Popowa as localities. 



dianulites HAYDENH Dybowski. 



Plate 2, figs. 11-116. 



Dianulites haydenii Dybowski, Die Chaetetiden der Ostbaltischen Silur-Forma- 

 tion, 1877, p. 37, pi. 1, figs. 11 a-h. 



Although Dybowski gives a detailed description and figures the 

 internal structure of this species, he shows no characters which 

 enable me to recognize what particular form he had in mind. With- 

 out a restudy of the type-specimens, if they are available, I fear that 

 Dianulites liaydenii can not be recognized. 



Occurrence. — Middle Ordovician, Wesenberg and Wassalem. 



DIANULITES SULCATUS Dybowski. 

 Plate 2, figs. 12-126. 



Dianulites sulcatus Dybowski, Die Chaetetiden der Ostbaltischen Silur-Forma- 

 tion, 1877, p. 38, pi. 1, fig. 12a, 6. 



The figures of this species are clearly of some Homotrypa or Homo- 

 trypella, but for lack of specimens from the type locality, I am unable 

 to decide the relationship of the form. If the zoarial growth shown 

 by Dybowski is constant, this alone should help in identifying the 

 species. 



Occurrence. — Probably Lyckholm limestone, Kertel, island of Dago. 



