SPECHTS FERRY BRYOZOAN FAUNA 17 



Genus PRASOPORA Nicholson & Etheridge, 1877 



Type species: Prasopora grayae Nicholson & Etheridge 



PRASOPORA SIMULATRTX ORIENTALIS Ulrich 



Plate 3, figures 7-9 



Monticulipora (Diplotrypa) Whiteavesii Nicholson, 1879 (in part), 

 Pal. Tab. Corals, William Blackwood and Sons, Edinburgh 

 and London, p. 316, fig. 42c, pi. 14, fig. 1. 

 Prasopora simulatrix var . orientalis Ulrich, 1895, Geol . Minnesota, 

 v. 3, p. 246, pi. XVI, figs. 1, 2, 6, 7; Wilson, 1921, 

 Geol. Survey Canada Bull. 33, pi. 3, figs. 1, 2; Fritz, 1957, 

 Geol. Survey Canada Bull. 42, p. 34, pi. XXVIII, figs. 2, 3. 

 External features. — Zoarium free, hemispherical, upper surface convex 

 and concentrically wrinkled, lower surface concave; zoarium from 8 to 12 mm in 

 diameter and from 1.8 to 3.9 mm thick. Low monticules or very slightly elevated 

 maculae approximately 1 mm in maximum dimension, consisting of angular meso- 

 pores flanked by zooecia above average in size, and spaced from 3.0 to 4.5 mm 

 apart, measuring from center to center. 



Tangential section. — Zooecia round, broadly ovate, or somewhat subangular, 

 having thin amalgamate walls; in intermacular areas most commonly (15 of 20 meas- 

 urements) seven entire zooecia and portion of eighth in 2 mm; less commonly (four 

 of 20 measurements) eight entire zooecia and part of ninth in this distance; rarely 

 (one of 20 measurements) six entire zooecia and part of seventh in 2 mm; average 

 maximum diameter (based on 30 measurements) of intermacular zooecia 0.26 mm, 

 ranging from 0.23 to 0.31 mm; average maximum diameter (based on 24 measure- 

 ments) of zooecia flanking maculae 0.37 mm, ranging from 0.32 to 0.44 mm. Ad- 

 jacent zooecia almost invariably in contact locally. Mesopores angular, not ex- 

 ceeding one-quarter of the size of a typical zooecium and generally smaller; four 



EXPLANATION OF PLATE 4 



Figure 5 is X2; figures 4 and 8 are X60; all others are X20. 



Specimen number and collecting locality are shown in parentheses follow- 

 ing explanation of each figure; for example, (12P211, 10) refers to specimen 

 12P211 obtained from collecting locality 10. Structures in photographs are not 

 retouched . 



Figure 



1-8 Heterotrypa pauca Perry, n. sp. 1. Tangential section of holotype 



(12P211, 10). 2. Tangential section displaying larger zooecia 

 flanking monticule in upper left and thin-walled zooecia in lower 

 right where section is locally below mature zone (12P211, 10). 3. 

 Longitudinal section of holotype (12P211, 10). 4. Longitudinal 

 section (12P185, 8). 5. Surface of zoarium showing monticules 

 (12P228, 6). 6. Longitudinal section in which mesopores are more 

 abundant than normal for species (12P178, 8). 7. Tangential sec- 

 tion showing well developed monticule in upper third of illustration 

 (12P178, 8). 8. Tangential section showing zooecial wall structure, 

 small acanthopores and a single mesopore (12P70, 6). 



