STOMOTOCA DIVISA. 203 



the Panamic species, the ovaries in S. atra being dark brown or blackish 

 (Agassiz, '65, p. 169), while in S. divisa they are pinkish; and by the fixct, 

 which I have been able to corroborate on the original specimens now in the 

 collection of the Museum of Comparative Zoology, that there are fewer rudi- 

 mentary tentacles, the maximum observed being forty in S. atra as against 

 about one hundred and twenty in S. divisa. 



Stomotoca divisa Maas. 



Stomotoca divisa Maas, '97, p. 11, taf. 1, figs. 1-9. 



Plate 7, fig. 9; Plate 43, figs. 6, 7. 



Station 4600 ; surface, October 15 ; many specimens, 8 mm. to 12 mm. 

 in diameter. 



Station 4644 ; surface, November 7 ; 15 specimens, up to 25 mm. in 

 diameter. 



The specimens in the first capture were all rather small ; but when the 

 species was taken again, three weeks later, all but one were much more 

 advanced, the largest measuring about 25 mm. in diameter. 



The gonads present a very interesting condition. In the smaller speci- 

 mens the condition is very similar to that described by Maas ('97). As he 

 states, the gonads are continuous interradially at the base of the manubrium, 

 though so deeply cleft in the interradii as to be horseshoe-shaped ; the arms 

 of the horseshoe, lying on either side of the perradii, are complexly folded. 

 This is essentially the same condition as in Tiara and other Tiaridae, in all of 

 which the gonads are primarily interradial. So far as I know, no student 

 has demonstrated that the gonads in any Tiaridae or Amphinemidae .are ever 

 entirely subdivided in the interradii. It is therefore of great interest to find 

 that such is their final state in tlie largest specimens of S. divisa; and I 

 believe that the number of specimens (fourteen) in wliich I have found this 

 extreme type is sufficient to establish it as the normal adult condition. There 

 is no doubt, however, from the conditions in younger specimens, that the 

 gonads are primarily interradial ; and it is to be noted that in their final 

 condition they are not in any sense radial, since they always remain entirely 

 separated in the perradii. The complete separation of the two arms of each 

 horseshoe-shaped gonad is probably the result of rapid growth on the part 



