Diplotrypa negleota.] 



' BEYOZOA. 



Diplotrypa negleota, n. sp. 

 1 



287 



Fig. 19. Diplotrypa negleota Ulrich, base of Galena limestone, Hader, Goodhue county, Minnesota. 

 Collection of E. O. Ulrich. 1 and 2, two tangential sections, x 18, and 3, a vertical section, similarly 

 enlarged. 



Zoarium a small subconical or hemispheric mass, about 12 mm. in diameter and 

 8 mm. in hight. Tube walls thin, transversely rugose, appearing quite irregular 

 and rough in longitudinal fractures. Zooecia about nine in 3 mm., not regularly 

 arranged, polygonal, largely in contact with each other, the mesopores being few in 

 number and variable in size and distribution. Clusters of large zooecia occur and 

 among these the mesopores may be more abundant than in the intermediate 



spaces. 



In transverse sections we see cells of all sizes up to 0.45 mm., and not infre- 

 quently it is difl&cult to discriminate between the smaller zooecia and the mesopores. 

 As is shown by vertical sections the two sets of tubes are not totally distinct, 

 the mesopores being in many cases clearly superseded by zooecia. Perhaps on 

 account of the rugosities of the walls the mesopores often appear as developed 

 periodically. The diaphragms are irregularly distribute^, from one-half to four 

 times their diameter distant in the large tubes and averaging about 0.15 mm. apart 



in the mesopores. 



Though possessing all the essential characters of the genus, the internal irregu- 

 larly and other peculiarities of the species are so obvious that comparisons are 

 unnecessary. 



Formation and locality.— howei part of the Galena limestone, at Hader, Goodhue county, Min- 

 ta It is here associated with Mesotrypa (?) rotunda Ulrich, Plectatnbonites gibbosus W .and S., 

 T^rocystitea angulatus Ulrich, Fusispira ventricosa Hall, and other fossils described in this volume. 



