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



triangular, and sculptured transversely with rather widely spaced 

 grooves, which are waved downward near the sides of the area. The 

 base of this area is formed b}' the carina. 



The carina has a recurved, overhanging apex. The surface is divided 

 into two areas, that below the beak being concave and weaklj^ irregu- 

 larly wrinkled parallel to the base. The rostral area is sculptured with 

 four slightly curved o])lique ribs, the upper one much the largest, the 

 lower one very small. These ribs have roof-tile-like sculpture, and 

 their ends interlock with those of the rostrum. The furrow between 

 the first and second ribs is much wider than the other furrows. 



The rostrum is shaped much like a mirror image of the carina, but 

 the wall below the beak is vertical, not concave, and there is a ledge 

 above, with two beaded radial ribs curving toward the movable scu- 

 tum. Below this ledge there is a very strong rib articulating at the 

 end with the carina, and below it two minor ribs, all transversely 

 grooved, the grooves narrow, intervals not much raised. The rest of 

 the plate has irregular wrinkles parallel to the base. 



Greatest carino-rostral length, 5.9 mm.; width at right angles to 

 length, -I mm. ; height from base to apex of the fixed tergum, 3 mm. 



This species differs from others having the movable plates parallel 

 to the base by the sculpture of four articular ribs, other species of 

 similar form having three or five ribs. V. calotheca was taken at the 

 same station as F. etiglypta. It differs from that species conspicuously 

 in the flat top and the shape and sculpture of the plates forming the 

 wall and in the simple, open interior. In V. euglypta the plates of 

 the wall are vaulted toward their apices inside. 



VERRUCA DARWINI, new species. 

 Plate X, figs. 4-7, 8. 



Type.—Cvit. No. 9015, U.S.N.M. 



Type-locality. — Alhatross Station 2042, east from Cape May, north 

 latitude 39° 33', west longitude 68^ 26' 45", in 1,555 fathoms. 



The shell is white, much elevated, seated lengthwise on the slender 

 spine of a sea urchin; the base therefore is long and narrow, partially 

 clasping the spine, and the side walls overhang. The movable scutum 

 and tergum slope steeply at an angle of about 45° with the base. All 

 of the plates are concentrically sculptured with wide, flat pleats. 



The movable scutum is sculptured with wide transverse pleats, cut 

 by an arcuate sulcus running from apex to the baso-tergal angle, 

 cutting ofi' an arcuate particular ridge. The small area between this 

 rib and the tergal margin is closely sculptured with fine riblets parallel 

 to the latter. 



The quadrangular movable tergum is divided into two areas by a 

 well-raised, arcuate diagonal I'ib from apex to baso-scutal angle. The 



