HAW Air AX CIRRIPEDIA. 



18 it 



The lergum (pi. v. t\g. fi outside, fig. S inside) is triangular. ?culplured like the «'utum, liut show- 

 ing weak radiating stria?, also, and with a sharp ridge followed l)y a depressed Inmd near and jjarallel to 

 the scutal margin. The carina! margin is straight, the l>asal a little concave, and the scutal margin is 

 slightly convex. The articular ridge projects far on the scutal side, sloping inward, and is about half as 

 long as the scutal margin, frcmr which it is seijaratcd by a deep articular furrow. Inside the apical and 

 scutal margins of the valve and articular ridge are margined liy a wide border sculptured with growth 

 lines. Elsewhere the valve is smooth and white. 



The carina (pi. v, fig. 1,3) is shaped much like that of Balunus, or like the anterior valve of a chittm, 

 since it surrounds the opercular valves behind and at the sides. Outwardly it is tripartite, with a 

 median curved triangle (the "roof"), sculptured with aljout five unequal low radial ridges, and two flat 

 lateral triangles: the whole being sculptured with wide-spaced grooves parallel to tlu' basal margin and 

 parted liy flat intervals. The \imbo is apical. The lateral l)orders are .somewhat rrrnvdated. 



Fig. 4. — Catophragmu.^ daru-ini. .v. Ma.xiUa; b. mandible: c, caudal appendage; i«. tiftli eirriis. 



The carino-lateral plate (pi. v, fig. 1, CI.) consists of a triangular, erect, radially six-ril)bed ana ami 

 a projecting ribless triangular wing on the occludent side above: the whole sculptured with spaced 

 grooves parallel to the basal marign, becoming olilique on the wing. 



The rostrum (pi. v. fig. 2, 5 1 resembles the carina in shape, but is smaller, with only tliree prominent 

 radial ribs. The rostro-lateral ])late (pi. v, fig. 2, Rl) is triangular, .sculptured with four wide rd)s and 

 the usual spaced grooves parallel to the basal margin. The plates of the next lower or third whorl are 

 small, subtriangular, and of three .shapes, doulily winged (pl.v, fig. 2, lower left-hand plate), winged 

 on one side (fig, 2, lower right-hand plate), or without lateral wings (fig, 2, intermediati.' plate i. The 

 base is unknown. 



The mandibles (fig. 4, B) have three large teeth and a group of denticles at tin- lower extremity. 

 The maxilla; (fig, 4, a) have the usual pair of strong spines above; the lower moiety of the margin pro- 

 jects beyond the upper, l)Oth being densely bristly. The first pair of cirri is much shorter than the 

 others, with wider rami, each of 10 joints, densely l>ristly. The rami of the third pair have about 21 

 joints and are like those of the following ciiTus. The posterior cirri have about 25 joints. The rami of 

 each ciiTus are subequal throughout and are much curled; they have small tufts at the articulations, 

 and a continuous series of long spines along the concave side, about four pairs of spines on each joint 

 (tig. 4. D, fifth cin'us). The caudal appendage is long and slender, of 13 joints (fig. 4. c). The peni.^i 



