. The fur seals and fur-seal islands of the North Pacific ocean. Sealing; Seals (Animals). TUNICATA OP THE PEIBILOF ISLANDS. 517. it. (Fig. 13.) Brancliial sac with four folds on each side, the development of these folds varying with the size (age?) of the specimen. In smaller (youT)ger'?) specimens the folds on the left side more strongly developed than those on the right. In speci- mens to cm. (including peduncle), pair of folds next the endostyle had about 12 bars and those next dorsal lamina about 20. In specimen to cm. folds next endostyle had about C and those next dorsa
. The fur seals and fur-seal islands of the North Pacific ocean. Sealing; Seals (Animals). TUNICATA OP THE PEIBILOF ISLANDS. 517. it. (Fig. 13.) Brancliial sac with four folds on each side, the development of these folds varying with the size (age?) of the specimen. In smaller (youT)ger'?) specimens the folds on the left side more strongly developed than those on the right. In speci- mens to cm. (including peduncle), pair of folds next the endostyle had about 12 bars and those next dorsal lamina about 20. In specimen to cm. folds next endostyle had about C and those next dorsal lamina about 12 bars. Folds closely placed, only 3 to 5 bars between them. Transverse vessels of three sizes, a wide one (Tri, iig. 11) occurring at irregular intervals, and two narrower ones (Trz and Trj), which usually alternate with each other. Intermediate transverse vessels (Tr^) some- times present, often dividing the series of stigmata into two. Meshes nearly square or longitudinally elongated with 4 to 6 (usually 5j long narrow stigmata. (Fig. 11.) Dorsal lamina ribbed on one side by the ves- '^ sels passing round the oesophagus. Digestive tract.— Situated on the left side of branchial sac and making a narrow turn. CEsophagus short, opening from the dorsal side of the branchial sac near its posterior end. Stom- ach long and narrow, with numerous in- ternal folds which show on the surface as longitudinal markiugs. Anal open- ing bilobed, each half cut into about six lobes. (Fig. 12.) Sexual organs.—Gonads on each side of the body. Ovaries long, sausage shaped, ending in a short oviduct, those on the right side longer than those on the left. One of those on the left side placed in the loop of the intestine, the other beginning higher up and extending down under the stomach. Testis small, clustered in bunches over the ovaries. Endocarps rather numerous on the mantle. The genus Styela is naturally divided into two sections—those in which the species are pedunculated
Size: 1169px × 2139px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, bookpublisherwashingtongovtprin
