characteristic of the group (fig. 1). S. I. Smith's investigations on the early stages of _Hippa talpoida_, Say, were published in 1877. [Illustration: FIG. 1.--_Neolithodes grimaldii_, A. Milne-Edwards and Bouvier.] With regard to the accessions to knowledge in the enormous group of the genuine Macrura, reference need only be made to the extensive reports in which Spence Bate, S. I. Smith, Faxon, Wood-Mason, Alcock, and others have made known the results of celebrated explorations. Various larval stages have been successfully investigated by Sars. Alcock (1901) describes from his own observation the newly hatched _Phyllosoma_ larva of _Thenus orientalis_, Fabricius. An admirable discrimination of the larval and adult characters of the genus _Sergestes_ has been given by H. J. Hansen (_Proc. Zool. Soc._, London, 1896). Singularity excites our wonder in _Thaumastocheles zaleucus_, v. Willemoes Suhm, which makes up for its vanished eyes by its extraordinarily elongate and dentated claws; in _Psalidopus huxleyi_, Wood-Mason and Alcock (1892), bristling with spikes from head to tail; in the Nematocarcinidae, with their long thread-like limbs and longer antennae; in species of _Aristaeopsis_ reported by Chun from deep water off the east coast of Africa, bright red prawns nearly a foot long, with antennae about five times the length of the body. That certain species, particularly many from deep water, have disproportionately large eggs, is explained by the supposition that the young derive the advantage of being hatched in an advanced stage of development. [Illustration: FIG. 2.--_Anaspides tasmaniae_, Thomson.]