26 BULLETIN 93, UNITED STATES NATIONAL MUSEUM. 



localities are: Albatross station 2268, off Hatteras, north latitude 

 35° 10' 40"; west longitude 75° 06'*10", in 68 fathoms, bottom tem- 

 perature 71°.3 F., and station 2269, in the same locality, 48 fathoms, 

 bottom temperature 77° F. On the Pourtales Plateau, 10 miles 

 south of Key West, 3^acht Eolis, J. B. Henderson, jr., 1911, all on 

 spines of Doroddaris. Off Florida, in 195 fathoms, Blake Expedi- 

 tion, in the Museum of Comparative Zoology. 



V. alba has a very considerable geographic range — greater than any 

 other American species so far as we know, but it seems to be restricted 

 to moderate depths, and it will be noted that the northern stations 

 have about the same high bottom temperature as the southern, and 

 all lie in the course of the Gulf Stream. 



The barnacle is white, flat topped, with steep or subvertical walls. 

 The movable scutum is strongly convex between the apex and basal 

 margin, the apex being depressed and somewhat twisted. It has 

 three articular ridges and two (or sometimes three) longitudinal ridges 

 on the occludent area. The movable tergum has four articular 

 ridges, the second one very small in the type-specimen (but nearly as 

 large as the others in another). The fixed scutum and tergum have 

 conspicuous, stout, recurved beaks. The carina and rostrum inter- 

 lock by one long and some small teeth in each; and above the upper 

 articulating rib botli carina and rostrum have several sliort riblets 

 curving toward and terminating on tlie scutotergal Jiinge line. There 

 is a shallow adductor pit in the fixed scutum bounded below by a 

 curved adductor ridge. The fixed tergum is calloused inside. TJie 

 basal edges of the wall are very obtuse, rather thick. 



Length 4, breadth 2.7, height 1.7 mm. 



The cirri are very slender. The first has rami of 11 and 21 seg- 

 ments, the anterior ramus not much exceeding one-third the length 

 of the posterior. Cirrus ii similar, of 9 and 19 segments, the anterior 

 ramus a third as long as the posterior. The rami of cirrus iii are more 

 nearly equal, the anterior three-fourths the posterior. Cirrus vi 

 about 3.3 mm. long. The terminal appendage is 2.8 mm. long, with 



27 segments, bemg nearly four times as long as the protopod of 

 cirinis vi. 



The above details from the original specimens, together with the 

 figures given in my former accomit, show that V. alba is widely 

 distinct from F. nexa Darwm, of which I formerly thought it might 

 be a variety. 



The specimens are apparently adidt, judging from the long beaks 

 of the fixed scutum and tergum, and the thickness of the wall plates. 

 The specimens from off Hatteras, one from each of the stations men- 

 tioned above, are typical in form and sculpture and of about the 

 typical size, one measurmg: carinorostral length 3.9, breadth 2.8, 

 alt. 1.9 mm. Specimens from other places differ in some respects. 



