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Family Polynoida

plate, fig, seta, head and length

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FAMILY POLYNOIDA. Lepideaotas laqurnue a. sp.

Length of type 14 mm.; greatest breadth at end of anterior third 4 mm.; body tapering from here in both directions, but the head is broader than the Pnidium• The head (plate 1, fig. 4) is oval with the transverse diameter the longer, with a narrow median posterior depression and a much wider anterior one, the latter filled with the base of the median tentacle. Posterior eyes very small and situated on the dorso-posterior surface, the anterior ones larger, on the antero-ventral surface, and not visible from above. At the anterior margin the head is continued into the bases of the lateral tentacles, with a constric tion at the base of the latter. Lateral tentacle not more than half as long as head, lanceolate, with acute tip. The other tentacles and tentacular cirri had been lost. Palps about 6 times the length of the head, perfectly smooth.

The body has 39 somites and 15 pairs of elytra. In alcohol the color is a yellowish brown with no trace of pigmentation except on the elytra. On each elytron a dark-brown pigment patch extends from the attachment of the elytrophore toward the median longitudinal line of the body. This is crossed by a definite white line at the position of the inner margin of the elytrophore and does not reach the edge of the elytron. (Plate 1, fig. 5.) First parapodium (plate 1, fig. 6) with prominent antero-dorsal lip on the neuropodium, the notopodium slender and cirrus-like, with an acicula and a bundle of delicate, curved, minutely denticulate seta. The ventral cirrus is very slender, reaching nearly to the tip of the neuropodium. A parapodium from the middle of the body (plate 1, fig. 7) has the neuropodia and notopodia much as in the anterior one, but the antero-dorsal lobe of the notopodium is more acutely conical in form. The dorsal cirrus has a stout basal joint, its terminal joint slender and tapering, extending beyond the apex of the para podium. The ventral cirrus is situated on the neuropodium about one-third of its length from the apex. Each lobe of the parapodium has an aciculum and the arrangement of seta is much as in the earlier somite.

In the middle parapodium are three kinds of seta: (1) Notopodial: these are all alike, each seta being very long and slender, curving gently toward apex and with very delicate teeth along one edge; fine lines across the seta possibly indicate minute plates of which the teeth are the free ends (plate 1, fig. 8).

(2) Dorsal neuropodial: with long slender shafts, but with the terminal third of the seta elongated lanceolate in form; minute transverse plates in this terminal third protrude from the margin so as to give it a minutely toothed appearance (plate 1, fig. 9).

(3) Ventral neumpodial: those lying next to the dorsal ones are much like them in length, but have heavier shafts and the terminal swelling is shorter, so that the lanceolate end is less elongated; the more ventrally placed ones are shorter, so that those on the very ventral side are not more than half as long as the dorsal ones; each (plate 1, fig. 10) has 5 or more rows of finely toothed plates beyond the base of the lanceolate portion, with very fine trans verse plates between the last of these and the apex of the seta. The apex in both kinds of ventral seta is bifurcate.

Collected July 6, 1915, on a Marphysa from Mangrove Key, in Key West Harbor.

Type in American Museum of Natural History.

Lepidasthenia Tarim, n. sp.

Body variable in number of somites and length; one entire individual of 50 somites measured 30 mm., while an incomplete specimen contained 80 somites and measured 48 mm. Greatest width of larger specimen 3 mm.

The head (plate 1, fig. 11) with sides smoothly rounded laterally and taper ing gently to the bases of the tentacles. The posterior margin is deeply in cised and a faint groove is carried over the dorsal surface to the base of the median tentacle. The greatest width is behind the middle, and this is about equal to the length. There are apparently 2 pairs of eyes, the anterior larger and situated on the antero-lateral surface, the posterior near the posterior margin of the head. Neither eye showed any pigment, their position being indicated by an elevated patch of whitish epithelium.

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