No. 1797. 



NEW TUBULIPOROID BRYOZOA—BASSLER. 



505 



CORYNOTRYPA DISSIMILIS SECTION. 



Angle of divergence very small, proximal constriction less dis- 

 tinctly marked, aperture slightly exsert, little constricted, walls 

 transversely wrinkled or smooth. 



a 



d 



CORYNOTRYPA DELICATULA SECTION. 



At least four species are known with characters so similar to the 

 genotype that they may be grouped with it into a section of the 

 genus as designated above. On account of their relations to G. 

 delicatula, these five species naturally are the most typical forms of 

 Corynotrypa, although the 

 following G. injlata section 

 comprises very similar, con- 

 generic forms. In the pres- 

 ent section the club-shaped 

 zocecia are very delicate and 

 usually greatly elongated, 

 the slender stolon being al- 

 most always well developed. 

 The angle of divergence in 

 the zooecia proper is so slight 

 that some care is required to 

 determine the distal end of 

 the stolon. This angle is 

 about 15° in G. delicatula, 

 and ranges from this to 30° 



in other species of the section. The aperture in both this and the 

 C. injlata section agrees in being constricted, with a diameter about 

 one-third that of the zooecium, and in being surrounded by a distinct 

 peristome. Views of average zooecia, equally magnified, of the five 

 species referred to this section of the genus, are assembled in figure 3 

 for convenience of comparison. 



Specific variation. — For reasons which will shortly be apparent, 

 this section exhibits an astonishing amount of variation in the same 

 species. This has been studied in only the type species on account 

 of abundant material, but similar variation will no doubt be found 

 in the other members of the section. Indeed, the variation is so 

 great in G. delicatula that at least four distinct names have been 

 appUed to the species. The types, or typical specimens of these 



Fig. 3.— Coeynoteypa delicatula section. Group or 



ZOCECLA, X20, SHOWING SPECIFIC DIFFERENCES. a, CORY- 

 NOTRYPA delicatula; 6, C. barberi; c, C. elongata; 

 d, C. nitida; e, C. tenuichoeda. 



