A near relationship between the Apterygota and the Crustacea has been ably advocated by H.
His earlier publications were on zoology; he dealt with the Amphibia (1839), Reptiles (1840), with Mollusca and Crustacea (1845) and more generally with the invertebrate fauna of the Mediterranean (1854).
Mention should also be made of the partial or complete atrophy of the eyes in many Crustacea which live in darkness, either in the deep sea or in subterranean habitats.
Their affinities with the lower Crustacea were recognized by Cuvier and his contemporaries, but it was one of the brilliant discoveries of that remarkable and too-little-honoured naturalist, J.
Under the heading Crustacea the Entomostraca have already been distinguished not only from the Thyrostraca or Cirripedes, but also from the Malacostraca, and an intermediate group of which the true position is still disputed.
Xxviii., and supplementary notices in Della Valle's Monograph of the Gammarini (1893)', the scope of his work, however, not covering the Hyperiidea and Oxycephalidae of Bovallius (1889, 1890); but since these dates very numerous additions to the literature have been made by Birula, Bonnier, Norman, Walker and others, especially the Crustacea of Norway, vol.
Many, perhaps the majority, of the Crustacea are omnivorous or carrion-feeders, but many are actively predatory in their habits, and are provided with more or less complex and efficient instruments for capturing their prey, and there are also many planteaters.
It seems likely that a similar explanation is to be applied to the coalescence of one or two trunk-somites with the head in the Copepoda, and, if this be so, the only Crustacea remaining in which no trace of a shell-fold is found in the adult are the Anostracous Phyllopoda such as Branchipus (fig.
The Crustacea are - with the exception of the Cirrhipedia - remarkable for having stiff, motionless spermatozoids.
P. 211 (1901); Sars, Crustacea of Norway, vol.