110 U.S. NATIONAL MUSEUM BULLETIN 272 



lobelike projections, or an irregular number of filaments of variable 

 length. 



Distribution. — Ranging from the type locahty in the European 

 U.S.S.R. west to Czechoslovakia and Germany, southeast to China 

 and Japan, recently also recorded from Austraha (Racek, MS.); as 

 subfossil remains recorded from Hungary (Traxler) and from sedi- 

 ments in Lago di Monterosi, Italy (Racek, MS.). 



Color in life. — Association with zoochlorellae quite frequent, 

 and color usually dark green, ranging to greenish j^ellow. 



Discussion. — The apparent absence of this species in western 

 countries, its rather obscure original description, and the great 

 variability of the terminal foraminal projections of its gemmules 

 have aU contributed to the regrettable fact that H. stepanowii remained 

 an ill-known species. The many descriptions by subsequent writers 

 of a range of "varieties," all based solely on the structure and shape 

 of the foraminal cirri, have only added to the abeady existing con- 

 fusion. Schroder (1927b) has to be commended for his pioneering 

 attempt to find a solution of this problem by comparative studies 

 of the gemmular porus tube in all spongiUids wdth heterogeneous 

 birotulate gemmoscleres. However, in spite of his convincing demon- 

 stration of the close relationship of all Heteromeyenia species with 

 acanthoxea as free microscleres and his justified abohtion of the 

 ill-conceived genus Carterius Petr, he too added to the confusion by 

 relegating H. stepanowii to mere "varieties" of his rediscovered 

 H. baileyi. Although, as shown in the discussion of H. baileyi, the 

 morphometric differences between the spicular components of H. 

 baileyi and H. repens are extremely insignificant, the H. stepanowii 

 complex displays a great number of such differences which justify 

 its clear separation from H. baileyi. 



Schroder's (1927b) revision furthermore failed to do away mth the 

 highly unstable additional criterion used by all previous authors for 

 the differentiation of the various species of Carterius Petr, i.e., the 

 extent and shape of the distolateral foraminal projections of the 

 gemmules. Petr (1886), in describing variations of this tube in E. 

 bohemica, expressed his views as to the possibihty of this species 

 being identical with H. stepanowii, and the shape and number of the 

 foraminal projections in Carterius stepanowii formae arndti, palatinus, 

 and petri are so similar that this criterion cannot possibly be retained 

 for their separation, even on a subspecific level. Recent studies of 

 H. stepanowii, found isolated in Austraha (Racek, MS.), revealed 

 the great variabihty of foraminal projections under different growth 

 conditions and made it obvious that this criterion alone is fully 

 unsuitable for racial discrimination within that species. 



