250 



BULLETIN 11, UNITED STATES NATIONAL MUSEUM. 



rounded at the distal end where possibly a second articulation 

 occurred. Surface free from monticules but hirsute because of the 

 great number of large acanthopores. Macules composed of zooecia 

 larger than usual are present but quite inconspicuous. About four 

 zooecia in 2 mm. Zooecial aperture subangular to rounded, the 

 shape depending upon the number of mesopores which vary in 

 number, but are sometimes so abundant as to isolate the zooecia. 



Fig. 143.— Lioclemella clava. a, the type-specimen, natural size; 6, tangential section, X20, 



EXHIBITING THE NUMEROUS LARGE ACANTHOPORES; C, VERTICAL SECTION, X8, ILLUSTRATING THE TABU- 

 LATION; d, PORTION OF THE SAME, X20. KEGEL BEDS (D2), HaBBINEM, ESTHONIA. 



Acanthopores both large and numerous, appearing at the surface as 

 blunt, perforated spines occupying the junction angles of zooecia and 

 mesopores. 



The most striking feature of tangential sections is the number 

 and size of the acanthopores. These are frequently so large that 

 the place of an ordinary mesopore is occupied by one, and four or five 

 may be noted about a single zooecium. The material composing an 

 acanthopore is of a lighter color and more granular nature than the 

 sohd, dark tissue making up the rest of the zoarium. The walls of 



