THE BARNACLES IN THE U. S. NATIONAL MUSEUM. 15 



No. 32873, a dry specimen: Length of capitulum 52, breadth 3H mm; 

 length of peduncle 35 mm; length of carina 53, diameter at base 7 nnn. 

 No. 32875, an alcoholic specimen; length of capitulum 50, breadth 34 

 mm; length of peduncle 58 mm; length of carina 49, diameter at base 

 8 mm. 



In the dry examples the peduncle is much shortened and the scales 

 become crowded. In the alcoholic individual taken by the Albatross 

 the peduncle is longer than the capitulum, and the scales are seen to 

 be arranged in circular whorls separated by chitinous nude intervals. 

 There are 15 such whorls, not counting some much smaller, irregu- 

 larly placed scales at the base of attachment, each whorl being com- 

 posed of about 17 scales. These are placed obliquely, the upper and 

 ventral end of each scale imbricating over the lower and dorsal end 

 of the following scale. 



The capitulum and peduncle are covered with a gra}" cuticle, which 

 is distinctly velvety to the touch. This was not apparent in the dry 

 examples, and hence was not noticed in the original description. 



In No. 32875 the carina is more robust, with the umbo removed a 

 little more from the summit of the plate than in the t3'pe lot. More- 

 over, the carina reaches farther up toward the apex of the tergum, 

 its end being at the upper fourth of the carinal margin of the tergum, 

 while in the type lot it is but little beyond the upper third. 



An alcoholic example taken by the Fisheries steamer Albatross gixQn 

 opportunity to examine the mouth parts and cirri. 



The mandible {Plate IV, fig. 4) has six larger teeth, counting the 

 blunt lower point, and two smaller ones. The lower point is covered 

 with minute spines. 



The maxilla (Plate IV, fig. 5) has a sinuous edge, closely set with 

 spines. There is a tuft of delicate hairs on the upper border. 



The first pair of cirri (Plate IV, fig. 1) has very unequal rami, the 

 anterior ramus shorter, with 12 segments greatly produced on their 

 lateral borders. The posterior ramus consists of about 16 segments. 

 The spines are chiefly seated on the distal borders of the segments. 

 The inner face of the cirrus is very densely spinose all over. 



The second pair of cirri is shorter than those following, with the 

 endopod a trifle longer than the outer ramus. Externally they show 

 a row of large spines along the anterior border, about five or six on 

 each of the lower segments, the number decreasing to one on the distal 

 ones. There are also groups of smaller spines at the sutures, along 

 the posterior margins. The whole inner face of the cirrus is densely 

 hairy. 



On the sixth cirrus, along the anterior side of each ramus, there is 

 a double series of long diverging spines, five spines on each joint. 

 Between each pair of large spines there is a group of small ones. 



