. Copepoda. Calanoida; Copepoda. 212 COPEPODA The labrum is, as seen in Wolfenden's fig. 41, more elongated than that of S. uiaguus (PI. VII fig. 8 a), and strongly produced in front; the hinder portion of the labrum is, as in most other species, marked by an anteriorly convex line. I am fairly convinced that the anterior as well as the posterior portion of the labrum belongs to the mandibular and not to the antennal somite; the anterior portion, accordingly, does not correspond to the epistoma of Euchcetc. The arrangement of bristles on the anterior surface is very characteristic (PI. VII fig
. Copepoda. Calanoida; Copepoda. 212 COPEPODA The labrum is, as seen in Wolfenden's fig. 41, more elongated than that of S. uiaguus (PI. VII fig. 8 a), and strongly produced in front; the hinder portion of the labrum is, as in most other species, marked by an anteriorly convex line. I am fairly convinced that the anterior as well as the posterior portion of the labrum belongs to the mandibular and not to the antennal somite; the anterior portion, accordingly, does not correspond to the epistoma of Euchcetc. The arrangement of bristles on the anterior surface is very characteristic (PI. VII fig. 7 b). In the middle, most anteriorly, is a forward convex row of about 30 long bristles. A little more posteriorly we have on each side a long row extending laterally from the middle in front towards near the hinder margin; the setae of this row are decreasing in length posteriorly; the right and the left parts establish an acute angle open posteriorly, and, thus include a more posterior row, forming a more obtuse angle, of shorter setae. In addition to the marginal setae, posteriorly irregular groups of short setae are found on each side. The oral surface of the labrum is rather characteristic, the first group is poorly developed, consisting of small granules and is well separated from the groups 2—4, which are more or less fused and consist of fairly strong, densely placed setae; behind, a group of small granules is observed (fig. 7 c, which is turned upside down). A lamina labialis (fig. 7 d PL VII), consisting of a median and two lateral parts, is found. In front of the serrula 6-dentata are two rather irregular rows of delicate setae, as seen in figure. Between the serrulae at least two groups of short spines and a longitudinal row are seen on each side. The lobus labialis possesses a wide inner row of numerous hairs, and an Text-fig. 66. Lophothrix frontalis Giesbr. outer one 0f few hairs; both rows start posteriorly from a. fO. Genital somite X 33- b. Y9 (St. V) Pes
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