154 " THETIS " SCIENTIFIC RESULTS. 



Family POETUNID^. 



Section PORTUNIN^. 



N E P T U N U S, De Haan. 



NEPTUNUS PELAGICUS, Linn. 



Neptunus pelagicus (Linn.), A. Milne-Edwards, Archiv. Mus. 



Hist. Nat., X., 1861, p. 320. De Haan, Fauna Jap., Crust., 



1835, p 37, pis. ix. and x. 

 Neptumis hituberculatus^ Miers, Ann. Mag. Nat. Hist., (4), 



xvii., 1876, p. 221. 



Stations 12, 23, 24. 



Pour specimens of this common species were obtained. They 

 exhibit considerable variation in the granulation of the cara- 

 pace, in the size of the median frontal teeth, and in the relative 

 elevation of the tubercles seated on the cardiac region. 



For comparison a large number of examples — both dried and in 

 spirits — from Port Jackson, have been examined ; these also 

 exhibit similar variations. In the largest male the carapace 

 measures 85 mm. by 182 mm. (lateral spines included). The 

 chelipedes are about 305 mm. in length ; the median frontal teeth 

 measure 2 mm. The tubercles on the cardiac region are ill- 

 defined, and not more distinct than a pair situated on the anterior 

 gastric region. The granules on the carapace are few, small, sub- 

 acute and distant, those seated on the main transverse lines are 

 1 -5 mm. or more apart ; on the shorter anterior transverse lines 

 and in the central regions they are somewhat closer, whilst on 

 the branchial regions they are more widely separated, varying 

 from 2 to 3 mm. in distance apart. 



In another male example the granules and median frontal 

 teeth are very small. The tubercles on the cardiac region are, 



