PLATE I. 
Big. Vtord: WVINELLAURIEPENS sUITICI:..orcisisitere aeele ctey eros ree ere ee eee ee te oree Rae e eee eee 
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 X18. The pores are absent, probably not having 
been preserved. 
3. Another portion of same zoarium X18, 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 zowcia were attached. 
4. Another specimen attached to a fragment of shell; natural size. 
5. Small portion of same, 18, 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.* 
Higss6andi7-ee SLOMATOPORA, DENUISSIMA MUI EICH ty cece ccieeerincte meeieteieis eerie ieiea sic crererele steisiaieietenmemteratele 
6. Portion of zoarium, 9, showing its slender zocecia and mode of growth, Utica horizon, 
Cincinnati group, Cincinnati, O. 
7. Several zocecia of same 25, to show their apertures and form more clearly. 
HiZS. SitOMlLZques LOMATORORA PROUDANAYS Aly Mill Creme ite eteterctenistsrecucielsleleleleiste bis e)sretenets erates siete aleiete 
8and 9. Zoarium natural size and portion *9. 
10. Several zocecia of same, *25. ; 
11. Several zocecia of same colony, a little more slender than usual, *25. 
12. Several cells of a form of this species in which they are unusually large, *25. (Survey 
Museum. Reg. No. 5926.) 
Middle third of the Trenton shales at Minneapolis and St. Paul. 
Migs, 1302] iS TOMATOPORA UNE TATA ELallllls rstctousefecrereisioc eine ois cricteicinissteid) vtrele ote = clereicieielemisysi cnet isiotele 
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 9, . 
17. Three zowcia of same, X18, one of them preserving traces of the minute pores that pierce 
the wall. 
18. Vertical section of one cell, X18. Upper third of the Trenton shales at Cannon Falls, 
Minn. 
19. Small portion of a large colony, *9, growing upon the concave side of Lepteena alternata; 
Cincinnati hills. 
20. Two zoccia of same, x18. In the Cincinnati form of this species the zowcia 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, *18, showing the unusual 
condition of three ‘‘gems” springing from one parent cell. 
Higgs; 22;ands23) STOMATOPORA TURGIDA IU Chi-. 5 sec cee uae eleteie cere eeu stsheererenis te ereisipls RANG ish Acie 
An example of this species growing upon Pachydictya splendens Ulr., natural size and 
same 9. Upper beds of the Hudson River gr., Wilmington, Il]. This species was 
recently discovered in the lower part of these beds in Fillmore county, Minn. 
Wiga24 a PROBOSCENAUEUM UE OS At IIS Permittee eieteelemeenetsrer utter ete sieietetfetoreretel ete yetetetsli /atatcunie tales oYayoval aateteretetere 
An example of this species, natural size and portion x9. Upper third of the Trenton 
shales, St. Paul, Minn. 
Figs..25 to'27. JBERENICEA MINNESOTENSIS: UITICHe me ccleele ie ccc sic o> os or epee sleeise snc sae! Jeveisie aisle\s edie 
25 and 27. Two specimens of the natural size. Near Minneapolis, Minn. The original of 
fig. 27 belongs to the Survey Museum. Reg. No. 5925. 
26. (29 on plate) Portion of original of fig. 25, x9. (See also Plate IT). 
Mig126.) ER OBOSCINASERONDOSA (NICHOLSON) ye aielefeletaatetetetetaie letersi istede ete rosie 'slefaie'e </eicte rains olsieieeieteterenetetsteveteras 
Portion of specimen showing mural perforations very clearly, x18, Cincinnati gr., Cin- 
cinnati, O. 
116 
117 
117 
118 
119 
120 
119 
*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. 
