On a remarkable Syllis-bud with extrudible segmental organs
Among a number of pelagic Annelids, collected in the Malayan Archipelago by Mr. D. S. Hoedt, I met with some fragments of a Syllis-species, characterized as well by its large orange-coloured eyes, as by a series of distinct brown spots on each side of the body. The largest fragment has a length of about 13 m.m., and is composed of 47 segments; another specimen, that seems to have an anal segment, measured only 9 m.m., the number of its segments amounting to 41. The head shows a deeply notched anterior margin, and is furnished dorsally and ventrally with two eyes of considerable size, resembling those of the Alciopidae; no cephalic processes are visible, neither tentacles nor palpi. Each foot (fig. 1) presents a dorsal and a ventral cirrus. The dorsal cirri are articulated and of a very different length, being in one segment thrice, in the other only once as long as the foot; the largest number of its articulations is 28. The ventral cirrus is smooth, acute conical, projecting somewhat beyond the apex of the foot. The feet are furnished with a fascicle of 4 to 6 bristles of the type, common amongst the Syllidae, with an elongated terminal appendage, bifid at the tip and beset with short hairs at the inner border (fig. 2a); the length of this terminal piece is not the same in all bristles, being in some of them one third longer as in others. Besides, the setigerous region of the foot possesses a dorsal tuft of long, translucent, paddle-shaped epitocous bristles; the tip of these ordinarily is bend and sometimes has a fimbriated appearance (fig. 2b).
|Journal||Notes from the Leyden Museum|
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Horst, R. (1889). On a remarkable Syllis-bud with extrudible segmental organs. Notes from the Leyden Museum, 11(1), 11–15.