REPORT ON THE ANOMtJRA. 103 



GALATHEIDEA. 



Galatheidce, Eoas, Vidensk. Selsk. Skr., G Ea'kke, nat. og math. AfcL, i, 2, p. 124, 1880. 



Carapace well developed ; the frontal region prominent, provided with a median 

 rostrum and frequently lateral processes. Eye-stalks short and stout. Antennal 

 peduncle composed of four segments (the second and third having fused); the flagellum 

 long and slender. Chelijaedes elongated and not markedly asymmetrical ; the first 

 three pairs of ambulatory limbs well developed, the ultimate pair slender and inflexed, 

 frequently chelate. Thoracic sterna broad. Abdomen symmetrical, composed of seven 

 segments, of which the first is usually concealed by the carapace ; the penultimate 

 segment with a pair of lamellar appendages, which form with the telson a broad 

 swimming fin ; the second segment in the males nearly always provided with genital 

 appendages. 



This group as instituted by Boas includes the Porcellanids and the Galatheids, which 

 were placed in separate subtribes by previous writers, several of whom had, how- 

 ever, noted their close affinities. The former must be regarded as highly specialised 

 Galatheids, which have to a certain extent assumed Brachyuran characteristics, 

 and though the abdomen still retains its primitive form, it has, in accordance with 

 altered life-habits, become reduced in size and of secondary importance as an organ of 

 locomotion. 



As in the case of the Paguridea I have retained, though with wider significance, the 

 subtribal name formerly applied to one of the sections only. 



Section A. PORCELLANODEA. 



Porcellaniens, Milne-Edwards, Hist. Nat. des Crust, t. ii. p. 246, 1837. 

 Porcellanidea, De Haan, Crust. Japon., p. 199, 1850. 



„ Dana, U.S. Explor. Exped., vol. xiii., Crust., part i. p. 400, 18.52. 



„ Stimpson, Proc. Acad. Nat. Sci. Philad., p. 65, 1858. 



„ Miers, Catal. New Zealand Crust., p. 59, 1876. 



„ Haswell, Catal. Austral. Crust., p. 145, 1882. 



Carapace broadly ovate, smooth, with the regions but faintly defined ; the front 

 usually trilobed, and the processes never of great length. Chelipedes broad and often 

 flattened, the ambulatory limbs robust and of moderate length. Antennules concealed ; 

 the antennal peduncle directed backwards. Eyes always pigmented and partially 

 concealed in orbits. External maxillipedes with the ischium broad, and the merus 

 provided with a prominent internal lobe. Abdomen bent under the thorax ; females 



