A New Genus of Phreatoicidae 221 



Body. — The surface of the body has very few setae upon it, 

 except the terminal segment, which possesses a fair number on the 

 back as well as on the hind margin, which also possesses some 

 spines and spinules. The side-plates of the pleon are fringed on 

 the inferior and posterior margins with a few long filamentous 

 setae, and the epimera of the last three segments of the pereion 

 have the posterior angle of each tufted with a few spinules. The 

 front margin of the head has also a few setae just above the base 

 of the lower antennae, in front of the place where the eyes in 

 allied forms are situated. 



Upper Antennae. — The first three joints which form the ped- 

 uncle are of subequal length, and conjointly scarcely reach 

 beyond the second joint of the lower antennae, the basal joint 

 is somewhat stouter than the succeeding one, the others become 

 a little narrowei'. The flagellum has seven joints, and, as in 

 Phreatoicus, towards the end is slightly swollen ; the first joint 

 is half the length of the preceding one (third joint of peduncle), 

 but scarcely any narrower. 



Loiver Antetinae. — None of the specimens possessed any that 

 were unbroken at the ends, so that their length is unknown. 

 The peduncle is relatively rather long and has very few setae ; 

 the first joint transverse, its lower margin longer than the 

 upper, the second almost square, third as long as the two basal 

 joints combined, proximally narrow and bent a little upwards, 

 fourth a little longer, fifth considerably longer than the fourth. 

 In the longest, but broken flagellum I counted 33 articuli. 



Month parts. — The mouth parts are of normal form. 



Anterior Lip. — Much broader than long, very thick at the 

 base, evenly rounded distally with the centre slightly produced. 

 Near the base of the lip (epistome) there is a distinct transverse 

 ridge projecting outwards and thickly furred. 



Mandibles. — The mandibles have no marked difference in shape 

 from the other allied forms. The most noticeable characteristic 

 is a rather stouter palp, the terminal joint being fully half as 

 broad as its length. The lejt mandible has the outer cutting 

 edge divided into four, and the inner into three teeth ; between 

 these and the molar expansion there is a secondary process (spine 

 row) and this bears on its summit about 14 pectinated spines 

 which are disposed in two parallel rows, which diverge from one 



