746 



CONTRIBUTIONS TO A KNOWLEDGE OF THE AUS- 

 TRALIAN CRUSTACEAN FAUNA. 



No. i. — Observations on the Genus Neptunus. 



By David G. Stead. 



Though the observations contained in this paper have all been 

 founded upon specimens of Neptunus pelagicus, M. Edw., they 

 will be found to apply equally as well to the other species of this 

 genus, jV. sanguinolentus, excepting in a few minor details, such 

 as the colour of the carapace, which in N. sanguinolentus is of a 

 lighter hue, is only minutely granular, and possesses three large 

 almost circular spots, somewhat similar to drops of blood, 

 surrounded by bluish-white rings, one on either side, on the 

 epibranchial regions, and one almost on the posterior border of 

 the carapace, over the intestinal region. So, but for these slight 

 differences, and a few others of small account, the two species 

 may be said to be morphologically the same. 



iV. pelagicus is the most common of our pelagic Brachyura, 

 being the principal edible crab of the Sydney Fish Markets, 

 lucidentall}'^ I might mention that great numbers of these are 

 sold every morning in these markets, with an occasional sprinkling 

 of four other species, viz., N. sanguinolentus, Scylla serrata, 

 Charyhdis cruciatus, and Platyonychus biptbstulatus* 



This species {N. pelagicus) is very abundant in Port Jackson, 

 and, though usually captured by the fishermen in the nets, may 

 also at times easily be caught with hook and line. When once 

 possessed of a good grip of the bait the}' seem very loath to let 

 go, thus enabling one to easily and effectually " land " them. It 

 may be here stated that, in the procuration of the Bi'achyurous 



* See my " Notes on tlie Habits of some of the Australian Malacostracous 

 Crustacea." " Zoologist," May, 1898. 



