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A REVISION OF THE SILURIAN BRYOZOAN 

 GENUS TREMATOPORA 



By RICHARD S. BOARDMAN 



Associate Curator of Geology 



United States National Museum 



Smithsonian Institution 



(With Two Plates) 



INTRODUCTION 



The genus Trematopora Hall, 185 1, is placed in the order Tre- 

 postomata of the Bryozoa and is the type genus of the family 

 Trematoporidae Ulrich in Miller, 1889. The type species of Tre- 

 matopora is T. tuberculosa Hall, 1852, from the Rochester shale in 

 New York (type by subsequent designation, Ulrich, 1882, p. 241). 



The name Trematopora was established in an article by the editors 

 of the American Journal of Science and Arts (Hall, 1851, p. 400) 

 in which parts of Hall's manuscript for volume 2 of the Paleontology 

 of New York (1852) were quoted. The species of Trematopora listed 

 following the diagnosis of the genus were nomina nuda and were not 

 published by Hall until the next year in volume 2. 



The development of the generic concept of Trematopora has been 

 controlled partly by the study and preparation techniques employed by 

 the various authors, each advance in technique adding refinements to 

 the original very generalized description. All the work of Hall and 

 Hall and Simpson (1851-1887) was done on external characters with- 

 out the use of thin sections. In fact, Hall's primary types of the type 

 species were sectioned for the first time for the present paper. Owing 

 in part to the external homeomorphy common in the Trepostomata, 

 Hall included in the genus many forms now placed in other genera, 

 families, and orders. At various times Hall considered such diverse 

 genera as Trematella Hall, Orthopora Hall, Chaetetes Fischer (part), 

 and Callopora Hall (part), as subgenera of Trematopora. 



Ulrich (1883, p. 257) was the first to section some "authentic speci- 

 mens of Trematopora tuberculosa Hall." These sections are in the 



SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 139, NO. 6 



