Vol. l] Kofoid. — Some New Tintinnidae. 293 



result from a symmetrical increase of the wall to from 2 to 2.5 

 times its thickness in adjacent regions. The anterior ring is 

 about one-fourth of the diameter of the mouth behind the rim, 

 the second ring three-fourths, and the third a little less than 

 five-fourths. The second and third are thus slightly nearer 

 together than the first and second. The total length of the lorica 

 is seven times its diameter between the rings and five times thai 

 on the rings. 



The lorica tapers very gradually near its middle to the si out 

 pedicel which with its terminal spine forms the posterior half 

 of the total length. This pedicel is about one-third of the 

 diameter of the anterior part measured between the rings, and 

 changes in the posterior third of its length from a cylinder to 

 a rectangular prism from whose flaring end arises the stout 

 terminal spine. The four angles of the pedicel are carried out 

 (on the skirt-like expansion) in projecting points like those of 

 C. quadridens and in addition one similar point is intercalated 

 on each margin of the overhanging ledge midway between the 

 two corners of each face. The width of the faces is about one- 

 fourth the diameter of the mouth of the lorica. 



The cylindrical spine projects from the center of the recessed 

 region at the base of the pedicel and ends in an acute tip. Its 

 length is nearly one-half the diameter of the mouth, and its 

 diameter less than one-fifth of its own length. 



The cavity of the lorica conforms to the external contour 

 with the exception that there are only very slight annular expan- 

 sions beneath the rings, and that in the prismatic portion of the 

 pedicel the lumen contracts suddenly to a slender canal which 

 extends as a straight tube nearly to the end of the terminal 

 spine. 



The structure of the lorica is essentially similar to that of 

 C. quadridens. It is composed of similar elements having a 

 similar arrangement in all parts but the rings. In C. quadridens 

 the wall is everywhere composed of a single layer of prisms but 

 in C. pulclira the rings, as shown in PI. XXVIII, Fig. 20, are 

 formed by 2-3 layers of prismatic elements, which pass over 

 into the single layer on either side. In the quadrangular sec- 



