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



that section of the genus which Miers defines as having the fourth joint of the 

 ambulatory limbs more or less spinose or tuberculated. All the six segments of the 

 pleon are also warty. 



Locality. — Off Pyramid Point, Ascension, from depth of 40 fathoms ; June 10, 

 1904; Station 507. 



Tribe CYCLOMETOPA. 

 Family XanthidtE. 



1898. Xanthidx, Alcock, Jour. Asiat. Soc. Bengal, vol. lxvii. part ii. p. 69. 

 1910. ,, Stebbing, Ann. S. Afr. Mus., vol. vi. part iv. p. 296. 



The family is here taken in the wider sense. 



Genus Xanthodius, Stimpson. 



1859. Xanthodius, Stimpson, Ann. Lye. Nat. Hist. New York, vol. vii. p. 52. 

 1901. „ Rathbun, Bull. U.S. Fish Comm. for 1900, vol. ii. p. 27. 



A. Milne-Edwards, who gives the reference to Stimpson as on p. 6, thinks that 

 Stimpson distinguished Xanthodius from Leptodius on indifferent grounds, the crest 

 on the endostome in the former being incomplete, and often occurring in a recognised 

 species of the latter genus. Later authorities, however, appear to agree in upholding 

 Stimpson's determination, though Miss Rathbun does not insist on the character to 

 which A. Milne-Edwards refers, and Dr Young speaks of (subgenus) Leptodius 

 as having " endostome without trace of longitudinal carinse. 



Xanthodius parvulus (Fabricius). 



1793. Cancer parvulus, Fabricius, Ent. Syst., vol. ii. p. 451. 



1858. Chlorodius americanus, Saussure, Mem. Soc. Hist. Nat. Geneve, vol. xiv. p. 430 (14), pi. i. fig. 5. 



1860. Xanthodius americanus, Stimpson, Ann. Lye. Nat. Hist. New York, vol. vii. p. 209 (81). 



1879. Leptodius americanus, A. Milne-Edwards, Miss. Sci. Mexique, part v. p. 269. 



1897. Xanthodius parvulus, Rathbun, Ann. Inst. Jamaica, vol. i. No. i. p. 15. 



1900. Leptodius (Xanthodius) americanus, Young, West Indian Stalk-eyed Crust., p. 147. 



1901. Xanthodius parvulus, Rathbun, Bull. U.S. Fish Comm. for 1900, vol. ii. p. 27. 



1908. „ „ Verrill, Tr. Connect. Ac. Sci., vol. xiii. p. 340, text-fig. 12, pi. xiv. fig. 4. 



Miss Rathbun's identification of de Saussure's species with the Cancer 

 parvulus of Fabricius was based on " types examined." The description given by 

 Fabricius is therefore inexact, since he states the front to be entire, whereas it is 

 notched in the centre ; he speaks of the sides as tridentate, but they are quadriden- 

 tate, and he says that the feet are short, smooth, with fingers black at the apex. As 

 he is no doubt referring to the chelipeds, only the colour note is accurate, while the 

 limbs are not specially short, and have the wrist and hand rough, " eroded in reticulat- 

 ing lines." The thumb of the larger cheliped in the Scotia male specimen has a 

 large blunt tooth on the inner margin near the hinge, and two smaller teeth near the 

 apex ; the movable finger has a curved and hollowed apex and a median tooth on 

 the inner margin. The fourth joint of the third maxillipcds is short and broad. 



