GONIONEMUS SUVAENSIS. 107 



Gonionemus SUVaensis Agassiz and Mayer. 



Gonionemus suvaensis Agassiz and Mayer, '99, p. 164, pi. 5, figs. 14-16. 

 Gonionemus pelagicus Bigelow, : 04, p. 256, pi. 4, figs. 12-14. 

 Gonionemus hornelli Browne, : 05 b , p. 149, pi. 1, fig. 6, pi. 2, fig. 4. 



Plate 3, Figs. 4, 5; Plate 32, Figs. 1-7. 



Mangareva Harbor; surface; 12 specimens, ranging in diameter from 

 4 mm. to 10.5 mm. 



The high arched bell and the considerable length of the manubrium are 

 shown in the photograph PI. 3, fig. 5. As in Browne's specimens, the 

 manubrium is situated on a very low peduncle, which is just visible in the 

 side view in PI. 3, fig. 5. 



In the smallest specimen there are fifty-two, in the largest about eighty 

 tentacles ; all have sixteen otocysts, four per quadrant (PI. 32, fig. l). Each 

 otocyst contains a single spherical otolith (PI. 32, fig. 6). The tentacles are 

 of different sizes, the longest about one third as long as the bell diameter, 

 and stout ; their sucking discs, very prominent (PL 32, fig. 3), at about mid- 

 way of their length ; but the exact position of these organs depends somewhat 

 on the state of contraction of the tentacles. Even in the small specimens 

 gonads are present, while in the larger ones they are well developed and ap- 

 proaching sexual maturity. Their characteristic location, restricted to the 

 distal fourth or third of the radial canals, is well shown in the photographs 

 of side and oral views (PI. 3, figs. 4 and 5). In small specimens the sexual 

 organs consist of a more or less wavy fold on the oral surfaces of the radial 

 canals, but with advancing development the plications of the fold increase, 

 until finally they become very complex (PI. 32, fig. 5). The essentially 

 ribbon-like structure is always retained, there being no papilliform processes, 

 such as are formed in the closely allied genus Olindias. My figure of the 

 gonad of the Maldive specimen (:04, pi. 4, fig. 13) was incorrect in this 

 respect. An interesting abnormality was exhibited by one specimen which 

 had only a single radial canal, with one very large gonad (PI. 32, fig. 7). 



Color. — The gonads are brownish red ; tentacles and tentacular bulbs pale 

 yellowish. The Fiji specimens figured by Agassiz and Mayer ('99) had green 

 pigment spots at the bases of 1 he tentacles, while in the .Maldive specimen 

 (Bigelow, :04) these pigment spots were brown. There is thus consider- 

 able local variation in the pigmentation of this species. 



Gonionemus suvaensis differs from the G. veriens group not only structurally 



