Vol. l] Kofoid. — Some New Tintinnidae. 



29] 



region of the pedicel and is continued as a slender tube nearly 

 to the tip of the terminal spine. 



The wall of the lorica is relatively thick, especially toward 

 the oral margin where it measures 5 //.. It grows slightly thinner 

 posteriorly especially in the expanded region of the pedicel 

 and the terminal spine, where it measures only 2-3 n in thick- 

 ness. 



The wall is composed of minute subregular prisms mainly 

 hexagonal with occasional pentagonal or irregular ones, placed 

 so that their ends form the inner and outer surfaces of the 

 lorica. Their sides form the coarse subregular hexagonal 

 meshwork which Brandt ('96) has designated as the secondary 

 reticulum. The slightly rounded ends of the prisms form the 

 whole, or at least a part, of the inner and outer lamellae of the 

 wall. Under high magnification (PI. XXVIII. Fig. 18) the 

 outer lamella exhibits a very minute faint reticulation which 

 Brandt has called the primary one. The diameter of the meshes 

 of this primary reticulum is less than 1 ^, and that of the 

 secondary about 5 p.. In the pedicel the secondary reticulum 

 becomes indistinct and on the expansion and terminal spine it 

 disappears altogether, apparently as a result of the greater 

 thickness in the walls of the prisms. 



Well preserved specimens of the inhabitant have not been 

 observed within the loriea, though moribund individuals have 

 been found there in a few instances. 



This species varies considerably in the prominence and 

 angle of divergence of the four salient spines on the pedicel 

 and in the length of the terminal spine. The four spines are 

 usually symmetrical with respect to each other but instances 

 of asymmetry are occasionally seen (PI. XXVII. Pig. 9). It 

 belongs uncpiestionably to the form-cycle of Cyttarocylis treforti, 

 described by Daday ('87) from Naples, which, however, has two 

 lateral apophyses in place of a quadrangular expansion of the 

 pedicel. Similar lateral apophyses also occur on the spirally 

 striate form described by Cleve ('99a) as C. hebe var. 

 apophysata. C. xreforti occurs occasionally in the plankton of 

 the Pacific off San Diego, but it does not appear to intergrade 

 with the form here described as C. quadridens. 



