80 



BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



Heterooecium are shown below. Rhammatopora, Ohar'ixa, and Distelo- 

 pora all of Lang, 1915, are placed here doubtfully. 



Genus HETEROOECIUM Hincks, 1892 



Electrinidae in which there is an acanthostegous ovicell and the 

 opercular valve is situated at the proximal end of the ovicell. 



Genotype. — Heterooecium amplectens Hincks, 1881. Recent. 



The acanthostegous ovicell is a space comprised between the 

 frontal and the united hollow spines on the median line. 



Genus TENDRA Nordman, 1839 



Like Heterooecium but the opercular 

 valve is situated at the distal end of the 

 ovicell. 



Genotype. — Tendra zostericola Nord- 

 man, 1839-1842. Recent (Black Sea). 



Genus NITSCHEINA Canu, 1900 



The genus Nitscheina Canu, 1900 

 (printed in error, Nichtina, but plainly 

 established in honor of Doctor Nitsche), 

 established for the Membranipora mem- 

 branacea group with Cyphonautes larvae, 

 until recently was not recognized because 

 it was thought contrary to the rules of 

 nomenclature. Harmer, 1926, adopted 

 it, however, as quite regular because the 

 genotype M. membranacea (auct.), the 

 very common and well studied ancient 

 is formed which opens outwards species is "probably" not the species of 

 immediately on the distal side of Linnaeus. We wish to adopt the name 

 the operculum of the proximal zo- mUcheina in order to retain Membrani- 

 oecium. (After Levinsen, 1909.) , 



pora for the very numerous species, recent 



and fossil, incompletely known. However, we will not change M. mem- 

 branacea (auct.) to if. telacea Lamarck, 1876, which has never been 

 figured because it is absolutely trivial and even disastrous to students 

 to change an old established name of a well known and well studied 

 species on a simple" probability. 



NITSCHEINA TUBERCULATA Bosc, 1802 



Plate 5, fig. 6. 



1921. Membranipora tehuelca Robertson, Bryozoa from the Bay of Bengal, 

 Records of the Indian Museum, vol. 22, p. 47. 



Fig. 14. 



-Genus Tendra Nord- 

 man, 1839 



A, B. Tendra zostericola Nord- 

 man, 1839. A. Two zooecia, X 

 40, the uppermost with ovicell. 

 B. Two zooecia, X55, the upper- 

 most with ovicell. The two rows 

 of spines form a somewhat arched 

 roof across the frontal mem- 

 brance and thus a space (ovicell) 



