Boone, Crustacea, Cruise of "Alva," 1931 181 



dactyl, also some long, solitary bristles, mostly on the upper lateral 

 margin. 



The eye is very large, the stalk short, fleshy, the hemiovoidal cornea 

 set obliquely terminal, possessing excellent visual range. 



The antennulae are well separated by a wide spetum and have an 

 enlarged basal article, the second and third articles clavate ; the flagel- 

 lum fleshy, short, tapered and the antennulae fold transversely. 



The antennae have the basal article much enlarged, with the outer 

 distal angle produced in a large, lobate, acute tooth that lies in the 

 orbital hiatus; the second and third articles reduced; the flagellum 

 short, extending merely to the base of the cornea. 



The external maxillipeds are squarish, close-fitting, with the distal 

 meral margin slightly rounded. 



References: Pachygrapsus minutus A. Milne Edwards, Nouv. Ar- 

 ehiv. Mus. Hist. Nat. Paris, t. IX, p. 292, pi. 14, fig. 2, 1873.— 

 KiNGSLEY, Proc. Acad. Nat. Sci. Phila., vol. 32, "p. 201, 1880.— de 

 Man, Notes Leyden Mus. vol. V, p. 158, 1883 ; Archiv. f. Naturges., 

 Bd. 53, heft 1, p. 368, 1887 ; Journ. Linn. Soc. Zool., vol. 22, p. 

 148, 1888.— Cano, Boll. Soc. Nat. Napol. vol. Ill, p. 240, 1889.— 

 Alcock, Journ. Asiatic Soc. Bengal, vol. 69, pt. 2, p. 399, 1900. — 

 BoRRADAiLE, Proc. Zool. Soc. London, 1900, pt. 2, p. 592; Fauna 

 and Geogr. Maldive and Laccadive Arch., vol. I, pt. 4, p. 432, 1902. 

 — Lenz, Schenkenb. Naturf. Ges. Bd. 27, p. 370, 1905.— Rathbun, 

 Bull. 23, pt. 3, U. S. Fish Comm. p. 840, 1906 ; Mem. Mus. Comp. 

 Zool. vol. 35, p. 30, 1907 ; Trans. Linn. Soc. London, ser. 2, vol. 14, 

 p. 242, 1911.— Edmondson, Bull. B. P. Bishop Mus. Bull. V, p. 10, 

 1923.— Balss, H., Denksh. Akad. Wien, Bd. 99, p. 16, 1924. 



Subfamily : Plagusiinae. 



Genus: PERCNON Gistle. 

 Percnon pilimanus (A. Milne Edwards). 



Plates 92, 93 and 94. 



Type: This species was first reported from New Caledonia by M. 

 Balansa and the type is deposited in the Paris Museum. 



Distribution : New Caledonia, (A. M. Edwards, Miers, Boone) ; 

 Marquesas, (A. M. Edwards) ; Sandwich Islands, (A. M. Edwards; M. 

 J. Rathbun lists this species in her Report on Hawaiian Crustacea, 

 without citing any locality) . 



