PLATE I. 



PAGE. 

 Fig. 1 to 5. VINELLA REPENS Ulrich 114 



1. Two colonies attached to the inner side of a ventral valve of Strophomena septata W. 



and S.; natural size. 



2. Portion of one of the colonies magnified xi8. The pores are absent, probably not having 



been preserved. 



3. Another portion of same zoarium *18, showing a nucleus with five divisions of the 



tubular stolon radiating from it. This portion of the specimen also preserves some 

 of the pores marking the points where the zocecia were attached. 



4. Another specimen attached to a fragment of shell; natural size. 



5. Small portion of same, xis, with three tubes lying parallel with each other. The longi- 



tudinal lines are stronger than usual. 

 Upper third of the Trenton shales at St. Paul.* 



Figs. 6 and 7. STOMATOPOHA TENUISSIMA Ulrich 116 



6. Portion of zoarium, xg, showing its slender zooecia and mode of growth, Utica horizon, 



Cincinnati group, Cincinnati, O. 



7. Several zooecia of same X25, to show their apertures and form more clearly. 







Figs. 8 to 12. STOMATOPOKA PROUTANA S. A. Miller 117 



8 and 9. Zoarium natural size and portion xg. 



10. Several zooecia of same, *25. 



11. Several zocecia of same colonv, a little more slender than usual, x25. 



12. Several cells of a form of this species in which they are unusually large, X25. (Survey 



Museum. Keg. No. 5926.) 

 Middle third of the Trenton shales at Minneapolis and St. Paul. 



Figs.l3to21. STOMATOPORA INFLATA Hall 117 



13 and 14. A colony attached to inner side of a fragment of shell, natural size, and a portion 



of same x9. 

 15 and 16. Another colony, natural size and a portion xg. 



17. Three zocecia of same, xis, one of them preserving traces of the minute pores that pierce 



the wall. 



18. Vertical section of one cell, xis. Upper third of the Trenton shales at Cannon Falls, 



Minn. 



19. Small portion of a large colony, xg, growing upon the concave side of Leptcena alternata; 



Cincinnati hills. 



20. Two zooecia of same, xl8. In the Cincinnati form of this species the zooecia are more 



inflated, and the whole zoarium more compact, and the growth more luxuriant than in 

 the typical Trenton form. 



21. Several zocecia of another Cincinnati specimen, in outline, xis, showing the unusual 



condition of three "gems" springing from one parent cell. 



Figs. 22 and 23. STOMATOPORA TURGIDA Ulrich i18 



An example of this species growing upon Pachydictya splendens Ulr., natural size and 

 same xg. Upper beds of the Hudson River gr., Wilmington, III. This species was 

 recently discovered in the lower part of these beds in Fillmore county, Minn. 



Fig. 24. PROBOSCINA TUMULOSA, n sp 119 



An example of this species, natural size and portion xg. Upper third of the Trenton 

 shales, St. Paul, Minn. 



Figs. 25 to 27. BERENICEA MISTNESOTENSIS Ulrich. . . 120 



25 and 27. Two specimens of the natural size. Near Minneapolis, Minn. The original of 



flg. 27 belongs to the Survey Museum. Reg. No. 5925. 

 26. (29 on plate) Portion of original of flg. 25, xg. (See also Plate II). 



Fig. 28. PROBOSCINA FRONDOSA (Nicholson) 119 



Portion of specimen showing mural perforations very clearly, x!8. Cincinnati gr., Cin- 

 cinnati, O. 



It is to be understood that when the collection containing the specimens Illustrated on this and all of the following 

 plates of Bryozoa is not mentioned, they belong to the author. 



