WeRead Powered by ReaderPub
A Monograph on the Sub-class Cirripedia (Volume 2 of 2) / The Balanidæ, (or Sessile Cirripedes); the Verrucidæ, etc., etc. cover

A Monograph on the Sub-class Cirripedia (Volume 2 of 2) / The Balanidæ, (or Sessile Cirripedes); the Verrucidæ, etc., etc.

Chapter 270: PLATE 17. Genera—PLATYLEPAS, TUBICINELLA, AND XENOBALANUS.
By Charles Darwin
Open in WeRead

Explore more books like this:

Science - Biology

About This Book

This work presents a detailed monograph on the sub-class Cirripedia, focusing on various species of barnacles, including the Balanidæ and Verrucidæ. It includes comprehensive descriptions, classifications, and illustrations of these organisms, contributing to the understanding of their biology and taxonomy. The author examines their anatomical features, reproductive habits, and ecological roles, providing insights into their adaptation and evolution. The text serves as a significant resource for naturalists and biologists interested in crustacean studies, reflecting the author's meticulous research and dedication to the field.

PLATE 17.
Genera—PLATYLEPAS, TUBICINELLA, AND XENOBALANUS.

  • Fig. 1 a, Platylepas bissexlobata, shell of, viewed from the under side; A, rostrum; B, lateral compartment; C, carino-lateral compartment; E, carina. These letters are placed opposite the inward folds of each compartment forming the midribs.
  • 1 b, Platylepas bissexlobata, shell of, viewed externally.
  • 1 c,””scutum and tergum, viewed externally and separated.
  • 1 d,””lateral compartment, viewed from the inside, showing the inward folded wall or midrib; a′, ala; d, radius.
  • 2 a, Platylepas decorata, shell, viewed externally; A, rostrum; B, lateral compartment; C, carino-lateral compartment; E, carina. These letters are placed opposite the inward folds of each compartment.
  • 2 b,””minute portion of external surface of wall, magnified.
  • 3 a, Tubicinella trachealis, natural size; p, tubular soft lip leading into sack; s, scutum; t, tergum.
  • 3 b, Tubicinella trachealis, carino-lateral compartment of a young specimen, natural size; e, broken summit of wall; d, radius: the dotted lines, connecting the two figures, show the size and form which this compartment would have attained, if it could have grown without the summit constantly breaking away.
  • 3 c, Tubicinella trachealis, scutum and tergum viewed from within, and connected by layers of thickened membrane; the scutum is to the left-hand.
  • 4 a, Xenobalanus globicipitis, enlarged; b, skin of the porpoise, with the shell imbedded; at c the lower end of the prosoma of the included animal’s body is supposed to be seen through.
  • 4 b, Xenobalanus globicipitis, shell greatly enlarged, seen from above, with the basal membrane at the bottom; the peduncle-formed body having been removed.
  • A, rostrum, on the inner side of this and the adjoining compartments, the transversely ribbed sheath can be seen.
  • B, lateral compartment.
  • C, carino-lateral compartment.
  • E, carina; these compartments are separated by the sutures s s, which run from the top of the shell to the bottom, along the ends of the six rays formed by the adjoining portions of the inwardly folded compartments.
  • a, alæ, of rectangular shape.
  • d, pseudo, or complimentary radii.
  • 4 c, Xenobalanus globicipitis, small portion of external surface of wall of shell, showing the external lamina, a a, which consists only of narrow ledges (expanding and contracting) on each side of the longitudinal septa, c; b, the internal lamina.