406 



The peduncle of the uropods is thin and long; the rami are narrow, 

 lanceolate, and approximately equal in length. The telson is small, its 

 apex round, the margins concave in the distal part. 



Distribution: A circumtropical species known from the tropical 

 regions of the Atlantic, Indian, and Pacific oceans, the Mediterranean 

 and Red seas. It is found in surface layers up to a depth of 

 300-500 m. 



XII: Family DAIRELLIDAE Bovallius, 1887 



Small crustaceans, highly transparent, and with a flat rounded head. The 

 eyes occupy almost all of the head and are divided into dorsal and ventral 

 groups of ocelli. In females the flagellum of antennae I is reduced to a 

 single virgate segment and antennae II are absent. The oral appendages 

 are partially reduced: the mandibles lack a palp, maxillae I lack an inner 

 lobe, maxillae II are not bifurcated to the end, and the maxillipeds are 

 in the form of a single plate. 



The pereon is more or less flat dorsoventrally and somites I and II are 

 fused. The coxal plates are fused with the pereon. The most characteristic 

 morphological feature is the uniformity of structure of all the thoracic 

 legs: not one pair has a chela or subchela and the segments are cylindrical 

 and contain transparent glandular inclusions. The gilUs are located on 

 somites II- VI of the pereon and the oostegites on pereon somites II-V. 

 The rami of the uropods are free. The telson is very small. 



The family includes one genus. 



331 1. Genus Dairella Bovallius, 1887 



Bovaflius, 1887b: 24; 1889: 332; Stebbing, 1888: 1342. 

 The head is spherically bulged. Antennae I in females are shorter 

 than the head, in males longer. The labrum is asymmetrical: one lobe 

 is higher than the other and the notch of the distal margin is narrow. 

 In the mandibles the cutting plate is small, triangular, and has a straight 

 denticulate edge; the masticatory process has a rectangular flat apex, a 

 tuberculate grinding surface, and a broad dentate collar. The maxillae 

 are very small: the outer lobe of maxillae I has denticles on the apex 

 and is incurved such that it touches the lobe of the opposite maxilla; the 

 palp resembles a broad round plate with unevenly denticulate distal and 

 inner margins. Maxillae II are represented by basally broadened plates, 

 narrowing toward the apex and bearmg one-three small spinules. The 

 maxillipeds are in the form of quadrangular plates, with rounded distal 

 angles, and armed with some small spinules. All the mouthparts are 

 slender and weakly chitinized. 



