266 REV. T. R. R. STEBBING ON STALK-EYED CRUSTACEA MALACOSTRACA 



Genus Planes, Bowdich. 



1825. Planes, Bowdich, Excursions in Madeira and Porto Santo, p. 15, figs. 2a, 2b. 

 1910. ,, Stebbing, Ann. S. Afr. Mus., vol. vi. part iv. p. 320. 



This genus is placed by Alcock in his division Varuninse. 



Planes minutus (Linn.). 



Plate XXIV. 



1758. Cancer minutus, Linn., Syst. Nat., ed. 10, vol. i. p. 625. 

 1825. Planes clypeatus, Ex. in Madeira, etc., p. 15, figs. 2a, 2b. 

 1905. Planes minutus, Stebbing, Gilchrist's Mar. Invest. S.A. Crust., part iii. p. 43. 

 1908. ,, ,, Verrill, Tr. Connect. Ac. Sci., vol. xiii. p. 325, text-fig. 7, pi. xiii. fig. a-f, 



pi. xxvii. fig. 6. 



A very large number of specimens were obtained by the Scotia from the Gulf 

 weed on June 29 and 30 and July 1, 1904. In most cases the colouring is lost, but 

 in some instances there is a well-marked pattern of dark brown on a light ground. 

 In this species the third maxillipeds have the fourth joint much shorter than the 

 third, but quite as broad, the outer margin strongly rounded, the fifth joint inserted 

 in an excavation of the front margin of the fourth, and, when folded down, not 

 reaching beyond that joint's inner edge. The principal joint of the exopod does not 

 reach the end of the endopod's fourth joint. The specimen figured was rather per- 

 plexingiy distinguished by retaining as preserved a dark-brown colour and showing 

 oblique striae on both .sides of the carapace, while also the indent below the antero- 

 lateral angles was exceptionally well marked. 



Localities. — Saldanha Bay, South Africa, 25 fathoms ; Station 483. And also from 

 29° 54' N., 34° 10' W., to 33° 53' N., 32° 27' W. ; Stations 537, 538, and 539. 



Genus Plagusia, Latreille. 

 1806. Plagusia, Latreille, Gen. Crust, et Insect., vol. i. p. 33. 

 1900. ,, Alcock, J. Asiat. Soc. Bengal, vol. lxix. pp. 297, 436. 



1905. ,, Stebbing, Marine Invest. S. Afr. Crust., part iii. p. 46. 



1908. ,, Verrill, Tr. Connect. Ac. Sci., vol. xiii. p. 332. 



1910. ,, Stebbing, Ann. S. Afr. Mus., vol. vi. part iv. p. 322. 



Immature Form. 



1852. Marestia, Dana, U.S. Expl. Exp., vol. xiii. p. 487. 



1910. ,, Stebbing, Ann. S. Afr. Mus., vol. vi. part iv., p. 348. 



From the essential agreement of the mouth-organs in the adult and Megalopa 

 specimens it seems clear that the form which Dana assigned to his genus Marestia 

 is really a juvenile stage of Plagusia. Both forms occur abundantly together. In 

 his full account of the genus Alcock invites especial attention to a feature of the 

 third maxillipeds, that " their exognath has no flagellum." But this must be taken 

 with some limitation, since de Ha an figures a small flagellum for his Plagusia 

 (Icnhjics, and I find one in P. capensis. It is slender, without setse except at the 

 apex, the apex in the Megalopa stage indicating faintly a second joint. 



