252 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



some generations ago, of individuals of the two nearly allied races, 

 giganteum and atlanticum. 



[We have adopted the term "group intermedium" as a convenience 

 to include all these doubtful forms. It is not at all a distinct sub- 

 species and needs no extended description. Our specimens are very- 

 diverse in form and in color. Some colonies are long, slender, and 

 cylindrical, others short and thick. For the most part the elevations 

 on the surface of the test suggest papillae rather than processes or 

 spines. The outer surface of the colony is often finely denticulate or 

 wrinkled, a thing rather characteristic of most Atlantic forms. The 

 test is usually yellowish or pinkish flesh-color. One colony contains 

 zooids which are quadrangular in side view and have the dorsal 

 leucocyte masses thick, broad, and merged together along the mid- 

 dorsal line. Other specimens resemble typical atlanticum atlanticum 

 in the character of their zooids. So that at best we can say only 

 that there is great diversity within the group. Specimens repre- 

 senting this "intermedium" group were obtained by the Albatross off 

 the east coast of North America at the following stations : 



D. 2039, off Maryland; July 28, 1883; 2369 fathoms; surface 

 temperature 81° F.; one specimen, Cat. No. 6497, U.S.N.M. 



D. 2058, off Nantucket; Aug. 30, 1883; 35 fathoms; surface tem- 

 perature 58° F.; two specimens. 



D. 2092, south of Block Island; Sept. 21, 1883; 197 fathoms; 

 surface temperature 67.5° F.; one specimen. 



D. 2396, off Cape San Bias, Fla. Gulf of Mexico; Mar. 13, 

 1885; 335 fathoms; surface temperature 66° F.; one specimen, 

 Cat. No. 440, U.S.N.M. 



D. 2602, off Cape Lookout; Oct. 18, 1885; 124 fathoms, surface 

 temperature 78°; one specimen, Cat. No. 2729, U.S.N.M. 



D. 2626, off Charleston, S. C; Oct. 21, 1885; 353 fathoms; surface 

 temperature 76° F.; two specimens, Cat. No. 2737, U.S.N.M. 



D. 2667, off Fernandina. Fla.; May 5, 1886; 273 fathoms; surface 

 temperature 75° F.; one specimen, Cat. No. 794, U.S.N.M. 



D. 2669, off Fernandina, Fla.; May 5, 1886; 352 fathoms; surface 

 temperature 77° F.; one specimen, Cat. No. 797, U.S.N.M. 



D. 2673, off Charleston, S. C; May 6, 1886; 240 fathoms; surface 

 temperature 77° F.; one specimen, Cat. No. 804, U.S.N.M. 



D. 2675, off Charleston, S. C; May 6, 1886; 327 fathoms; surface 

 temperature 75° F.; one specimen, Cat. No. 6496, U.S.N.M. 



An unnumbered station "off Pensacola," Fla.; one specimen, 

 Cat. No. 2761, U.S.N.M.] 



Colony. P. atlanticum giganteum is of increased interest because it 

 has been extensively studied by European workers. The colony 

 undergoes considerable change in passing from the young condition 

 to extreme development. SmaD colonies are conic-cylindrical, semi- 



