TUERIS FONTATA. 209 



Turris Lesson, 1837. 

 sens. em. Hartlaub ('92) ; Maas (:04 c ). 



Tiaridae with complex gonads, each consisting of two adradial series of 

 regular transverse folds which are often bifurcate ; connected with one an- 

 other near the base of the manubrium by a series of irregular thickenings, 

 and throughout the interradii by a network; radial canals with large 

 glandular diverticulae. 



To the above diagnosis Maas (:04 c ) has added the statement that new 

 tentacles are interpolated in a fashion different from the course of devel- 

 opment in Tiara, but he gives no description of the process. Another 

 feature which may prove distinctive is the fact that in Turris the glandular 

 diverticulae of the radial canals are much more highly developed, and more 

 complex than they have been described in any species of Tiara. Indeed, 

 they may closely resemble the condition figured by Maas (: 04 c , pi. 2, fig. 

 10) for Catablema vesicaria A. Agassiz. Turris is easily distinguishable from 

 Catablema by the form of the gonads. 



The present collection contains a single specimen of Turris. On general 

 principles I am strongly averse to basing a new species on one specimen ; 

 but in the present case it is justified, inasmuch as the specimen in question 

 differs in several important particulars from either of the two known 

 Pacific species, T. pelagica Agassiz and Mayer (: 02), and T. brevicomis 

 Murbach and Shearer (: 03), as well as from the Atlantic species. It is 

 especially interesting from the possession of ectodermic pits apparently of 

 a sensory nature. 



Turris fontata, sp. nov. 

 Plate 39, fig. 8; Plate 42, figs. 5-11. 



Station 4576 ; surface ; 1 specimen in excellent condition. 



The single specimen is 22 mm. high ; and the complexity of the gonads 

 and great size of the ova make probable that it is close to maturity. The 

 bell is of the outline usual in the genus, being high; with a low rounded 

 apical projection; gelatinous substance thin. 



Tentacles. — There are sixteen large, five intermediate, and about forty 

 very small tentacles. The latter show all gradations from mere knobs 

 to tentacles with developed filaments (PI. 42, fig. 6), and the interme- 

 diate tentacles connect them with the fully developed stage. The large 



M 



