CIRRIPEDIA FROM THE PACIKIC COAST OF NORTH AMERICA. 199 



Thf carina is very long, oxtcnding to the upper third of the tergum, and is arc-uate, much more 

 strongly so aljove than below. The roof is slightly convex, nearly flat, the sides meeting it at right 

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



The upper lateral plate is quadrangidar, the scutal margin longest and concave, the tergal, carinal, 

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

 against the inframedian lateral plate. The rostro-lateral is sqtiarish, 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, somewhat wineglass-shaped, being narrowest 

 l)elow the middle, widening slowly above and rapidly at the base. The luubo is at the narrow part. 



The carino-lateral plate is very long — fully twice as long as wide. The lateral and carinal margins 

 are .suliparallel, the upper margin very oldique and near the base cin-ving out Vielow the carina, beyond 

 which the umbones bluntly project. 



The peduncle is short and slender, rather s[)arsely protected by large scales, of whicli there are 

 about six in any longitudinal row. 



Length of capitulum S.8 mm., breadth 3.3 mm., diameter 1.2 mm. Length of carina (i.il mm. 

 Length of peduncle 2 mm. 



Type, no. 32420, U. S. National Museum, from Albatross station 4353, od Point Loma Light-Hou.se, 

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



Chiefly notable for the long plates of the ba.ial whorl and the elongation of the whole capitulum. 

 It is very closely related to S. Jlavum Hoek, from the South Atlantic, lat. 46° 46' S., Ion. 45° 31' E., 

 in 1,375 fathoms, but differs by the quadrate rather than triangular rostro-lateral plate, its basal margin 

 being much longer than in .'>'. flariim, l)y the narrower sides of the carina, and the narrower carino- 

 lateral plate. Three specimens were on the same glassy spicide which bore the ty]ies of .■?. Iiirvalf. 



BALANID^. 



Balanus concavus Uronn. 

 Balanus concavus Darwin, Balanidse, p. 235. (i. ('. Martin, Maryland Geological Survey, Miocenj, p. 0', pljites .^.l, .14, 1904. 



Stations 4303 and 4304. Point Loma Light-Hou.se, vicinity of San Diego, in 21 to 25 fathoms; 4420. 

 East Point San Nicolas Island, 33 fathoms: 4492, 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 of the Virginia and Maryland Miocene and the more rugged, 

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

 are all referable to B. concavus. 



Balanus aquila, n. sp. 



[PI. VIII. fig. 5-8; pi. X. fig. 2; pi. xi, fig. 2.] 



.\ large species related to B. psittaciis (Molinai. Basis, pariete.s, and raflii (lermeated by pores, 

 but they are minute and inconspicuous except in the parietes. 



The wall is conical with small orifice, roughened by irregular rude ridges on the parietes, whitish 

 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 alas concealed. 

 The sheath is long, sculptured with minute thread-like transverse raised lines. Below it the interior 

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

 and solid 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 transversely striate 

 edges. 



The scuta (pi. viii, fig. 7, 8) are dull yellow inside, whiti.-^h beneath, a brownish-yellow cuticle 

 externally. The plate is curved inward on lioth tergal and occludent borders, 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 cut longitudinal 

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

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

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



