n8 DISCOVERY REPORTS 



St. 267. 23. vii. 27 (night). West of Angra Pequena, 550-450(^0) m., 4 juv. $$, 4-2-6 mm.; (second tube) 1 imm. $, 



6 mm. 

 St. 407. 12. vi. 30 (day). South-west of Cape Town, 950-800 m., 1 $, 13-4 mm. 

 St. 700. 18. v. 21 (day). North-east of Cape Verde Is., 2025-0 m., 1 $, 9-2 mm. 

 St. 1569. 12. iv. 35 (night). South-east of Durban, 1200-500 m., 2 $$, n-8 mm. and 13-6 mm. 

 St. 1604. 29. x. 35 (night). South-east of St Helena, 620-500 m., 1 juv. £, 7-5 mm. 

 St. 1606. 31. x. 35 (night). West of Angra Pequena, 600-500 m., 4 ??, 7-2-10-8 mm. and fragments. 

 St. 1761. 3. v. 36 (day). South of Madagascar and east of East London, 1800-650 m., 1 $, 6-4 mm. 



Distribution. This species is a bathypelagic form widely distributed in the temperate and 

 northern waters of the Atlantic. It has been recorded on many occasions from northern European 

 waters and once from the West Atlantic off Long Island, U.S.A. (Tattersall, 195 1). It has been re- 

 corded from South African waters, west of Cape Town (Zimmer, 1914; Illig, 1930), and seven of the 

 stations at which it was taken by 'Discovery' and 'Discovery II' are in the same area. The other 

 five stations are all in or near South African waters, three off the west coast and two in the Indian Ocean 

 to the east of Cape Colony. 



Genus Katerythrops Holt and Tattersall, 1905 

 1905 Katerythrops Holt and Tattersall, p. 117. 



Remarks. This genus is characterized by the inflation of the cephalic region of the carapace ; by the 

 short rostral projection which covers only the bases of the eyes ; by the long, relatively robust anten- 

 nular peduncles ; by the extremely small antennal scale, which is narrower and usually shorter than 

 the peduncle and with the apex very little, if at all, longer than the tooth terminating the outer margin; 

 by the presence of a well-marked ocular papilla on the eyestalk; by the very long sixth abdominal 

 somite which is longer than the fourth and fifth somites together ; by the very long uropods and the 

 triangular telson with unarmed lateral margins and narrow apex armed with two pairs of spines. A pair 

 of median setae or bristles may or may not be present. 



Three species have, up to the present, been referred to this genus, A. oceanae Holt and Tattersall, 

 K. parva Zimmer, and A. tattersalli Illig. I am now able to add a fourth species to the genus, 

 A. resimora. 



In A', parva and A. tattersalli the telson is very short and is shaped like an equilateral triangle with 

 the lateral margins almost straight and converging to a very narrow apex. In A. oceanae and the new 

 species the telson is pear-shaped with the lateral margins very convex proximally, but straight in the 

 middle region of its length and slightly concave distally so that the distal third of the telson is very 

 narrow and elongate. A. resimora closely resembles A. oceanae in the form, proportions and shape of 

 the antennules and antennae, but may be distinguished from oceanae by the very large, well-developed 

 eyes in which the cornea is considerably wider than the eyestalks and by the more produced rostral 

 plate with its characteristic upturned margins. A further difference may be seen in the armature of 

 the apex of the telson. In A. oceanae the outer pair of spines is very slightly, if at all, shorter than the 

 inner pair, but in A', resimora the outer spines measure less than a third of the length of the inner 

 pair. 



Katerythrops oceanae Holt and Tattersall, 1905 



1905 Katerythrops oceanae Holt and Tattersall, p. 117, pi. xx, figs. 1-6. 



1906a Katerythrops oceanae, Holt and Tattersall, p. 24. 



1906a Katerythrops dactylops Illig, p. 198, fig. 5A-B. 



191 1 b Katerythrops oceanae, Tattersall, p. 30. 



1930 Katerythrops oceanae, Illig, p. 432, figs. 55, 56. 



1 95 1 Katerythrops oceanae, Tattersall and Tattersall, p. 214, fig. 47A-F. 



