HAWAIIAN CIRRIPEDIA. 



189 



The tergum I pi. v. fig. (j outside, fig. 8 inside) is triangular, sculptured like the scutum, but show- 

 ing weak radiating stria.-, also, and witli a sharp ridge followed by a depressed band near and parallel i" 

 the -.in al margin. The carinal margin is straight, the basal a little concave, and the scuta] margin is 



I' jlii l\ convex. The articular ridge projects far nn tin- scuta! side, sloping inward, and is about half as 

 long as l he scutal margin, from which it is separated by a deep articular furrow. Inside the apical and 

 scuta! margins of (he valveand articular ridgeare margined by 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 Balanus, or like i he anterior valve of a chiton, 



nn,' ii surrounds the opercular valves behind and at the sides. Outwardly ii is tripartite, with a 

 median curved in angle (the '-roof" i. sculptured with aboul five unequal lofl radial ridges, and I wo llai 



la I oral triangles; the whole being sculptured with wide-spaced grooi es paralli I to the basal margin and 

 parted by flal intervals. The umbo is apical. The lateral borders are somewhal crenulated. 



b c 



Fig. i. Catophraffmus darwini. i, Maxilla; B, mandibl i d EMthclrrtis 



The carino-lateral plate (pi. v, lig. I, CI.) consists of a triangular, erect, radially six-ribbed area and 



a projecting ribless triangular wing on th icludenl side above; the whole sculptured with spaced 



grooves parallel to i he basal marign. becoming oblique on the wing 



The rostrum (pi. \. lig. 2, 5) resembles the carina in shape, but is smaller, with only three prominenl 

 radial ribs. The rostro-lateral plate (pi. v. lig. '_'. Rl) is triangular, sculptured with four wide ribs and 

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

 small, subtriangular, and of three shapes, doubly winged (pi. v, lig. 2, lower left-hand plate), winged 

 ..ii ..no side i lig. 2, lower right-hand plate., or without lateral wings tig. 2, intermediate plate). The 



base i- iinkiiow n. 



The mandibles (fig. -i, b) have three large teeth and a group ..i denticles al the lower extremity. 

 The maxillae . fig. 1, a) have the usual pair of strong -pines above; the lower moiety of the margin pro- 

 jects beyond the upper, both being densely bristly. The firsl pair of cirri is much shorter than the 

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

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

 each cirrus an- 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 

 (fig. 4. ii. fifth cirrus). The caudal appendage is long and slender, of 13 joints dig. -l.ci. The penis 



