476 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.43. 



Reproductive system. — Gonads very definitely sausage-shaped 

 masses, about 6 on each side of the body, placed transversely, those 

 of the left side situated in the dorsal intestinal loop. Testes and 

 ovary closely associated in the same mass, but not hermaphroditi- 

 cally (fig. 26 gon.). 



Many delicate endocarps projecting from the mantle in among the 

 gonads. 



This rather unique Styela seems to have more in common with 

 S. vestita (Alder) than with any other member of the genus. The 

 most striking feature is the gonads. Alder and Hancock (1907, p. 

 124) remark on the pecuHarity of the gonads in S. vestita, which resem- 

 ble considerably those of the present species, and state that "the 

 only other species in which we have met with the same arrangement 

 of these organs is in the Glandula mollis Stimpson." This state- 

 ment of the uniqueness of this type of gonads written more than a 

 quarter of a century ago, almost holds good to-day in spite of the 

 great number of species of Styela and closely related genera that have 

 since been described. The only other species that I have noticed 

 in the literature (though I have not examined quite all of it with 

 reference to the point) having a similar type of gonads is S. Jloccata 

 Sluiter, 1904. Here there are also five gonadial cylinders on each 

 side placed transversely. A particularly interesting fact is that the 

 four species mentioned as having this unusual style of gonads are very 

 distinct in various other particulars, and all belong to quite distinct 

 geographical regions. 



Another point deserving special attention is the double sj^stem of 

 folds in the stomach, as shown in figure 24 st. It will be seen that in 

 addition to the oblique folds on the outer surface and anterior half 

 of the organ, there is a set of longitudinal folds on the posterior half. 

 A fact concerning these last that is not very clearly brought out by 

 the figure is that these longitudinal folds are a modification in direc- 

 tion of the set of obhque folds of the inner surface of the stomach. 

 Finally, the rigidity of the animal, the regularity of its shape, and the 

 heavy uniform coat of black sand, make the species very distinct, 

 even in so large an assemblage of species as that constituting the 

 genus Styela. 



The collection contains about 90 specimens from Albatross station 

 3270, lat. 55° 26^ 30'' N.; long. 162° 52' W., depth 16 fathoms (type 

 locality) ; and about 15 specimens from station 3288, lat. 56° 26' 30" 

 N.; long. 160° W., depth 15 fathoms. The first of these hauls was 

 made on June 26, 1890, and the second on July 17 of the same year. 

 Both stations are in Bering Sea, the first in the extreme eastern part 

 in Bristol Bay, the second a little west of this. 



The haul from station 3288 also contained Agnesia heringia. 



TVpe.— Cat. No. 5687, U.S.N.M. 



