General Catalogue of South African Crustacea. 415 



HEMILAMPROPS PELLUCIDA, Zimmer. 



1908. Hemilamprops pellucida, Zimmer, Yaldivia Exp., vol. viii., 



p. 172, pis. 39, 40, figs. 53-59. 



Specimens taken in lat. 35 9' S., long. 18 32' E., outside 

 the Agulhas Bank, from a depth of 564 m. 



FAMILY DICID^E, n. 



For the characteristics see the discussion under the new genus, to 

 receive which the new family is proposed. 



GEN. DIG, u. 



Third and fourth pedigerous segments of the trunk dorsally 

 coalesced. Telson elongate, almost parallel-sided to the short 

 triangular apex, which covers a pair of small anal valves. First 

 antennae with large first joint, the flagella small, the accessory 

 flagellurn two-jointed, minute. Mandibles with large spine-row, 

 molar well developed, accessory cutting-plate only on one member 

 of the pair. First maxillae with bisetose palp. First maxillipeds 

 with row of strongly pectinate spines bordering the antepenultimate 

 joint ; the branchial apparatus apparently without gill-sacs. Third 

 maxillipeds with second joint much dilated distally and third joint 

 exceptionally large. First and second peraaopods with well-developed 

 swimming-branches ; third and fourth peraeopods with these exopods 

 conspicuous, but devoid of natatory setae. Pleon of male showing no 

 trace of pleopods. Inner branch of uropods three-jointed. 



In the coalescence of tbe third and fourth trunk-segments this 

 genus agrees with Diastylopsis, S. I. Smith ; the remarkable telson 

 scarcely differs from that of the species which Dr. Caiman has pro- 

 visionally named Diastylis tubulicauda; the lips, mandibles, first 

 and second maxillas, and to a great extent the first and second 

 maxillipeds, resemble those structures as figured by Professor Sars 

 for Hemilamprops rosea (Norman) ; the distally much-dilated second 

 joint of the. third maxillipeds occurs in Paclujstylis rotundata, Hansen, 

 in Paradiastylis brachyura, Caiman, and elsewhere. If the affinities 

 of the new genus may be considered to connect it either with the 

 Lampropidae or the Diastylidas, in favour of the former alliance it 

 may be said that there the branchial elements are scattered and 

 much less fully developed than in the Diastylidas, and pleopods are 

 sometimes wholly wanting in the male as well as the female. On 

 the other hand, the inner ramus of the uropods is said to be always 



