298 



BULLETIN 93, UNITED STATES NATIONAL MUSEUM. 



The barnacle is conical, rounded or oblong, tliin, smooth, or with 

 rounded ribs, not eroded, or but very slightly worn, covered with a 

 thin cuticle; compartment easily separable from one another and 

 from the surface of attachment ; radii developed, narrow. Color very 

 light bluish gray or olive brown. 



Carinorostral diameter, 5 mm. ; lateral diameter, 3.5 mm. Carino- 

 rostral diameter, 5.5 mm. ; lateral diameter, 3.3 imn. 



Scutum rather broad, the apical angle less than a right angle; 

 the articular ridge has a rounded outline, gradually tapeHng down- 

 ward and upward. The adductor muscle pit is smaller than in 

 stellatus, but deep; its tergal margin is straight and very slightly 



Fig. 82. — Chthamalus feagilis. a, maxilla. 6, terminal segment of shorteu 



UAMU^ OF CIRItUS II. C, KLEVENTH SEGMENT OF CIRRUS VI. d, PART OF THE LABRUM, 



ALL FROM Albatross Station 2004. e, terminal segment of shorter ramus of 

 CIRRUS II, Ocean City, N. J. f, Chthamalus stellatus, Naple.s, tenth segment of 

 cirrus VI. 



raised, so that there is the trace of an adductor ridge in some speci- 

 mens. The exterior has conspicuous but very low growth-ridges, 

 and usually a fine longitudinal striation. 



Tergum not varying much from that of typical stellatus, except 

 that on account of the nearly perfectly preserved scutal margin, the 

 articular ridge appears less prominent. There is a short, rounded 

 and broad spur, decidedly more developed and broader than in ! 

 stellatus. 



The labrum is strongly concave in the middle, and on both sides 

 the edge is spinose (fig. S2d). 



The mandibles, palpi, and maxillae do not differ materially from 

 those of O. stellatus, figured on page 303. 



Cirrus i has slightly unequal rami of 7 and segments, armed 

 with simple spines. Cirrus ii has slightly unequal rami of 7 and 5 



