CIRRIPEDIA FROM THE PACIFIC COAST OF NORTH AMERICA. 199 



The carina is very long, extending to the upperthird of the tergum, and is arcuate, much more 

 strongly so above than below. The roof is slightly convex, nearly flat, the sides meeting if al right 

 angles, but without ribs at the angles. The sides are widest near the'apex. 



The upper lateral plate is quadrangular, the scuta! margin longest and concave, the tergal, carina!, 

 and basal margins shorter, subequal, nearly straight. The lower anterior angle is cut off, abutting 

 against the inframedian lateral plate. The rostro-lateral is squarish, as high as wide, the upper and 

 side margins subequal, the basal margin decidedly shorter. The umbo is at the upper occludent angle. 



The inframedian lateral plate is very long and narrow, Bomewhal n ineglass-shapi d, being nan 

 below the middle, widening Blowly above and rapidly at the base. The umbo is at the- narrow part. 



The carino-lateral plate is very long fully twice as long as wide. The lateral and carina! margins 

 are su I >] parallel, the upper margin very oblique and mar the base curving out 1" low the carina, beyond 

 which the umbones bluntly project. 



The peduncle is short and slender, rather sparselj protected by large scales, i i which th< n an 

 about six in any longitudinal row. 



Length of capitulum 8.8 mm., breadth 3.3 mm., diameter 1.2 nun. Length of carina 6.6 mm. 

 Length of peduncle 2 mm. 



Type, no. 32420, U. S. National Museum Erom Albatross station 1353, off Point Loma Light-House, 

 vicinity of San Diego, in 639 fathoms, on a glassy spit r spicule; gray mud bottom. 



Chiefly notable for tin- long plates of the basal whorl and the elongation of tin- whole capitulum. 

 li is very closely related to S. ftavum Eoek, from the South Vtlantic, lat. 16 16' S., Ion. 15 31' E., 

 in 1,375 fathoms, but differs by the quadrate rather than triangular rostro-lateral plat.-, it- basal in 

 being much longer than in S. flavum, by the narrower sides of the carina, ami the narrower carino- 

 lateral plate. Three specimens were on the Fame glass} spicule whii h bore the types of >'. larvale. 



HALAMDi:. 



Balanus concavus Bronn. 



Balanus concavus Darwin, Balanidee, p. !3S Q. C. Martin. Maryland Geological Survei m oei w, plat 



Stations 1303 and 1304, Point Loma Light-House, vicinitj of San Diego, in 21 to 25 fathoms; 1420, 

 East Point San Nicolas Island. 33 fathoms; 1492, Santa Cruz Light-House, 26 fathoms. 



The specimens belong to the small, conic, pink-striped form already known from Panama. This 



race is very unlike the large form ol the Virginia and Maryland Miocene and the a 



irregular specimens of the Caloosahatchee Pliocene, but Darwin considers that such varying 

 arc all referable to /;. concavus. 



Balanus aquila, n. sp. 



[PI. vni. fig. 5 8; pi. x. fig. 2; pi. \i, fig. _'. 



A large species related to /.'. psittacus (Molina). Basis, pariete . and radii permeated by pore 

 but they are minute and ii i picuou i o ept in the parietes. 



The wall is conical with small orifice roughened by irregular rude ridges on the p i i rhitish 

 where not covered with a bright yellow cuticle, which remains chiefly near the base. It is thick, 

 strong, and dense, porous only in the outer layer. The radii are rather narrow, the alse concealed. 

 The sheath is iong. sculptured with minute thread-like transverse raised lines. Below ii the interior 

 is white with some yellow stains, and closely, irregularly striated. The while basis is level, thin, 

 and olid except for a very few pores which in some places penetrate its lower or attached portion. 

 The sutures are inconspicuous and smooth within, but the separated plates show transverselj striate 



edges. 



The scuta (pi. vni. fig. 7. 8) are dull yellow inside, whitish beneath, a brownish-yellow cuticle 

 externally. The plate is curved inward on both tergal and occludent border-, but more so on the 

 former. The basal margin arches upward and is quite arcuate, bringing the baso-tergal angle above 

 the middle of the valve's length. The surface is sculptured with close, fine, deeply mi lomritudjnal 

 grooves, decussated by shallower, wider transverse or concentric furrows, cutting the stria' into beads 

 or granules. Inside, the scutum has a sharp, raised and reflexed articular ridge, and a dee]., narrow 

 articular furrow. There is a strong adductor ridge, not confluent with the articular ridge. Inside the 



