SYSTEMATIC REPORT 123 



Colour. There is a note in the bottle which reads, 'deep purple in colour with brilliant golden 

 eyes '. 



Remarks. This species strongly resembles Katerythrops oceanae Holt and Tattersall in the general 

 form of the anterior end, the inflation of the carapace anterior to the cervical sulcus, the shape of the 

 short rostral plate, the spacing of the widely separated eyes and the very small narrow antennal scale 

 with a relatively robust antennal peduncle. It may, however, be distinguished from this species as 

 follows: (1) by the absence of a tooth or spine on the outer margin of the antennal scale, (2) by the 

 absence of an ocular papilla and by the shape of the eye, (3) by the form of the telson. In Katery- 

 throps the eye is ovoid with its widest part half-way along the stalk ; the cornea is small and there is 

 a well-developed ocular papilla on the dorsal surface of the eyestalk. In Katerythrops the telson is 

 triangular and considerably longer than broad at its base with the lateral margins more or less 

 concave. The apex is narrowly truncate and armed with two pairs of spines. In the Discovery 

 specimen the telson is an equilateral triangle with the lateral margins straight and converging to 

 a very narrow apex. In shape it recalls the telson of Erythrops. 



In the absence of male specimens and owing to the damaged condition of this specimen, I am unable 

 to gauge the true taxonomic position of this new genus. It is certainly very closely related to both 

 Erythrops and Katerythrops. 



•Distribution. The type specimen was taken in a closing net in a vertical haul from 600 m. to 

 500 m. off the west of Angra Pequena. 



Genus Erythrops G. O. Sars, 1869 



1863 Nematopus G. O. Sars, p. 233. 

 1869 Erythrops G. O. Sars, p. 325. 



Erythrops africana sp.n. 



Occurrence: \ ! §- 9 ) 



St. 277. 7. viii. 27 (night). Off Cape Lopez, West Africa, 63(-o) m., 10 6*<?> 4'4~4'6 mm., 19 ?? with brood sacs, 

 3-8-4-6 mm., 22 juv. and $5 without brood sacs, 3-2-4-2 mm. Types. 



Description. Carapace produced anteriorly into a short, pointed rostrum which only just covers 

 the bases of the eyestalks ; emarginate posteriorly, leaving the last two thoracic somites exposed in 

 dorsal view. Sternal processes. In the middle of the sternum of each thoracic somite in the male there 

 is a peculiar club-shaped, spiny process similar to that found in E. serrata (G. O. Sars), the only 

 difference being that it is relatively larger and the spines arming the distal end are considerably longer 

 and more irregularly placed. In E. serrata similar processes occur in immature females as well as in 

 the males but, although a number of young females in the present material have no oostegites, none of 

 them has sternal processes. The specimens are not in good condition and it may be that these females 

 are in fact adult but have lost their oostegites. In Fig. 29 A I have dissected away the bases of some 

 of the thoracic appendages, in order to show these sternal processes of the male in situ (Fig. 29 A, C). 

 Antenmdar peduncle showing marked sexual dimorphism; twice as stout in the male as in the female; 

 third segment of the male swollen especially dorsally, and with the outer distal angle considerably 

 produced; in the female the outer distal angle of the second segment also is produced and tipped 

 with two or three setae. I have figured, to the same scale, the right antennules of a male and a female 

 of the same size, so that the very marked difference between them may be appreciated (Fig. 29D, E). 

 Antenna. Peduncle slightly shorter than the antennular peduncle; third segment the longest; scale 

 slightly arcuate; outer margin entire, terminating in a strong tooth which is equal in length to the 

 small apex ; scale very narrow, eight times as long as broad ; extending beyond the antennular peduncle 



16-z 



