EAKLY PALEOZOIC BRYOZOA OF THE BALTIC PROVINCES. 211 



lated walls characteristic of the typical members of the genus, and 

 two others conspicuous mainly for their extravagant development 

 of small acanthopores indenting the zocecial cavity. 



Genotype. — Stigmatella crenulata Ulrich and Bassler. Earliest 

 Silurian (Richmond), Ohio Valley. 



STIGMATELLA MASSALIS, new species. 

 Text fig. 115. 



Zoarium, a dome-shaped or hemispheric mass, which in the type- 

 specimen is 40 mm. in diameter and 20 mm. high. Surface smooth; 



/ 



Fig. 115.— Stigmatella massalis. a, side view of the type-specimen, natueal size; 6 and c, tan- 



GENTUL section, X20, AND A PORTION OF THE SAME, X35, PASSING THROUGH THE ZONE IN WHICH 

 ACANTHOPORES ARE DEVELOPED; d, VERTICAL SECTION, X8, PASSING THROUGH TWO LAYERS OF ZOCECIA; 

 e, PORTION OF THE SAME SECTION, X20;/, PART OF VERTICAL SECTION, X20, THROUGH A MACULA. KEGEL 

 BEDS (D2), HABBINEM, ESTHONIA. 



maculae inconspicuous, composed of zocEcia larger than usual. 

 Zooecia polygonal, thin- walled, seven in 2 mm.; mesopores almost 

 entirely wanting; restricted to the maculae when present; acantho- 

 pores usually few and inconspicuous at the surface. 



The extreme simplicity and thinness of the zocecial walls, the clear 

 space or white line in the walls separating adjoining zooecia, and the 



