PLATE II. 



Page 



Fig. 1. BeKENICEA MINNESOTBNSIS Ulr 121 



Small portion of the original of plate I, flg. 27, x]8, showing zooecial apertures less con- 

 stricted than usual, and portions of two non-celluliferous spots, 



Figs. 2 and 3. Diastopoeina flabbllata Ulr 121 



A complete zoarium of this species, of the natural size and x7, showing arrangement of 

 zooecial apertures, fine interstitial strife, and obscure coaeentric wrinlsles. A small 

 tubiculous annelid is attached to the frond. Upper part of the Galena shales at Can- 

 non Falls, Minn. 

 3. Portion of same xi8, to show the characters of the species more clearly. 



Figs. 4 to 6. MiTOCLBMA (?) MUNDULUM Ulr .^ 121 



4 and 5. Two fragments, nat. size and > 9. 

 6. Original of flg. 5, xi8. 



Upper part of the Galena shales at Cannon Falls, Minn. 



Fig. 7. Abtheoclbma billingsi Ulr 19' 



View of the type of this species, natural size. (Introduced to show mode of growth pre- 

 vailing in this genus.) 

 Trenton limestone, Ottawa, Can. 



Figs. 8 to 11 , 25, and 28 to 33. Aetheoclbma aematum Ulr 20: 



8. Large segment of the primary series, showing a sharply defined articulating socket; nat- 



ural size and xis. This figure was inadvertently placed upside down. 



9. Opposite side of another segment of the primary set, xi8. This and the preceding 



specimen is as thick as any noticed but not as long. 



10. Complete segment of the secondary set, x 18. 



11. Upper three fifths of another secondary segment, finely preserved, xi8. Upper part of 



the Galena shales near Cannon Falls, Minn. 

 25. Vertical section, x25, of a primary segment somewhat doubtfully referred to this species. 



Upper third of the Trenton shales, St. Paul, Minn. 

 28. Transverse section of a small segment (?secondary) x25. Gannon Falls, Minn. 

 29 and 30. Transverse and vertical sections of small segments found associated with the 



original of flg. 25. 

 31 and 32. A transverse, and the lower half of a vertical section, x25, of full-grown primary 



segments. Cannon Falls, Minn. 

 33. Vertical section of a secondary segment, eqally enlarged and from the same horizon and 



locality as the preceding. 



Figs. 12 to 15. Abtheoclbma pulchellum Billings 19 



12. Vertical section of secondary segment, x25. 



13. Transverse section of primary segment, X25. 



14 and 15 Transverse, sections, X25, t)f two secondary segments, one with six, the other 

 with seven rows of zooecia. These sections were prepared from authentic examples ^ 

 collected at Ottawa, Can., from the Trenton limestone. 



Figs. 16 to 21 and 23. Aetheoclbma coenutum Ulr ; 2C 



16. A continuous series of four primary segments, natural size, and three of them x7, 



showing the articulating sockets near the base of each. 



17. A similar series of segments, consisting of seven of the secondary order, natural size, 



with flive of them X7. 



18 and 19. Two segments of the secondary order, xi8, one with three cycles of zooecial aper- 

 tures, the other with four. They differ also in the ornamentation. 



20 and 21. Opposite sides of rather small but very perfect primary segment, natural size 

 and X18. (See also plate III.) 



23. Transverse section of primary segment, xi8, showing five rows of zooecia. 

 Middle third of the Trenton shales at Minneapolis, Minn. 



Figs. 22 and 24. Abtheoclbma steiatdm, n. sp 1! 



Tangential section, X28, and tranverse section, xi8. (See also plate III.) 

 Figs. 26 and 27. AETHEOcnBMA sp. undet , 2( 



Two segments, the first incomplete, showing slight differences in ornamentation; xi8. 



Trenton shales near Fountain, Minn. 



