288 STEPHANOMIA AIMPHITRIDIS. 



join the stem. Haeckel states that there are six irregular rows in his nereidum, 

 but he gives no further details. The bracts which lie dorsal are roughly bilateral, 

 proximally pointed, and distally tridentate (Plate 18, fig. 8). Those covering 

 the lateral faces of the siphosome are irregular in outline, and often much dis- 

 torted, perhaps as the result of crowding. They are usually tridentate, with a 

 fourth tooth on one of the margins (Plate 18, fig. 7). Many of the ventral 

 bracts, between which the tentacles are protruded, have a peculiar cup-like 

 recess on one of their margins (Plate 18, fig. 6), but this is not always the case 

 (Huxley, '59, p. 72). All the bracts are soft and foliaceous, thickest near the 

 middle, and very thin at the distal margin. 



The cormidia have been described by Huxley, but the location of the 

 various zooids is more precise than he supposed. In the present series there 

 are nineteen siphons, with corresponding segments of stem, and in all of them 

 the arrangement is as follows :—r Proximal to any given siphon there are from 

 2-5 palpons; distal and close to it are the two gonodendra, 9 and cf, and 

 crowded against them 3-6 palpons. On the pairs the cf cluster is always next 

 the siphon (Plate 18, fig. 2). Next to the 9 gonodendron there is a vacant 

 space occupied only bj' bracts; but midway between every two siphons there 

 is a cluster of 3-6 palpons of different ages. These intermediate groups are 

 clearly shown in Huxley's figure ('59, pi. 6, fig. 1); and they are represented as 

 filaments in the original figure of the species. Haeckel states that in nereidxwi 

 the "long internodes were free" ('88b, p. 221), but without figures or a detailed 

 account of the location of the palpons it is impossible to judge how much weight 

 should be attached to this statement. 



Each siphon has a well-defined basigaster. The palpons, each provided 

 with a filament, are of the usual type. The gonophores have been described 

 so fully by Huxley ('59) that I need mei'ely call attention to the fact that the cf 

 bells have tentacular rudiments on the margin (Plate 18, fig. 4, T. B.). Each 

 9 bell contains a single large egg. The tentilla of the "Albatross" specimens, 

 with short involucre and single terminal filament (Plate 18, fig. 3) agree very 

 well with Huxley's account. In the development each tentilla passes through 

 the usual series of changes (p. 280). 



In life the basigaster of each siphon was pale reddish, the tentilla brilliant 

 scarlet. Bracts, palpons, and stem were colorless, the former very transparent. 



The original specimen of the species was taken in the Atlantic; it is re- 

 corded from the Pacific (Huxley), from the Malaysian region (Lens and Van 

 Riemsdijk), and probably from Ceylon (Haeckel). 



