1900.] FROM THE FALKLAND ISLANDS. 505 



the eyes are simple. Professor Smith, in describing his SeypliaceVn 

 aremcola, says " eyes prominent, round," and " eyes black," a two- 

 fold notice from which so important a character as " eyes simple '' 

 could scarcely have been omitted had it been applicable. The 

 figure of the species by Harger ( Kep. U.S. Comm. Fisheries for 

 ]878, pt. 6, pi. 1. fig. 2) shows well-developed eyes with numerous 

 components. 



Gren. TrichOjVISCUS J. F. Brandt. 



1833. Tricho7iiKcas, Brandt, Consjjectus Crust. Oiiiscodorum, 

 p. 12 (Bull. Soc. Moscou, vol. vi. p. 174). 



1838. Itea, C. L. Koch, Deutschlauds Crustaceen, 22 (162\ 

 no. 16. 



1S40. Tr!cJto)iiscns, Milne-Edwards, Hist. Nat. Crust, vol. iii. 

 p. 174. 



1844. Itea, Zaddach, Synopseos Crust. Prussicorum Prodromus, 

 p. 15. 



1853. Sti/loniscHs (part.), Dana, U.S. Expl. Exp. vol. siii., Crust, 

 p. 736. 



1857. Philour/i-ia, Kiiuihau, Xat. Hist. Kev. vol. iv. p. 281. 



1868. Philoiigriit, Bate &' Westwood, Brit. Sess.-eyed Crust, 

 vol. ii. p. 454. 



1870. Trichoniscas, Budde-Lund, Nuturh. Tidsskr. ser. 3, vol. vii. 

 p. 227. 



1885. Trichoniscvs, Budde-Lund, Crust. Isop. Terrestria, p. 243. 



1886. Philygna (preocc. Diptera, 1844), Thomson & Chilton, 

 Tr. New Zealand lust. vol. xviii. p. 157. 



1886. Philygria, Chilton, ibidem, p. 159. 



1898. Trichoniscnfi, Sars, Crustacea of Norway, vol. ii. p. 1 60. 



To this genus Budde-Lund in 1885 assigns nine species, one of 

 them being T. as/ier Koch, found iu amber, and another the 

 Sci/phacella arcnicola of Smith, alread}' referred to. He makes the 

 Trichonucus Icydigi of Weber a synonym of his own T. alhidiis, but 

 this decision is not admitted by Sars. Uollfus added to the genus 

 the species cJiavest in 1888, insidai-is in 1889, and with some 

 doubt murrayi and arisfralis in 1890. In 1898 Sars instituted a 

 new genus, Triehoniscoides, to receive 7'rir7ion{scus alhidus Budde- 

 Lund, T. leydigi Weber, and perhaps 7'. cavernicoJa Budde-Lund. 

 He does not mention Trichonisani vividus Koch, but that species 

 should probably be transferred, as it has sim})le eyes ; and the most 

 prominent, thougli not of necessity the most important, distinction 

 of the new genus is that the eyes are simple or wholly wanting, 

 whereas in Trichoniscus they are •' small, but distin(;t, consisting of 

 only 3 visual elements imbedded in a dark pigment." In 1885 

 Chilton described a marine species from New South Wales as 

 Philougria marina, but the eyes apparently have numerous visual 

 elements, the mandibles show no mohr, and the other mouth- 

 organs are undescribed ; so that this species cannot be included in 

 Trichoniscns. In 1886 the same author described Philygria thom- 

 soni from New Zealand, and this appears to be a true Trichoniscus. 



[49] 



