2-4 BULLETIN 93, UNITED STATES NATIONAL MUSEUM. 



Conia monstruosa O. G. Costa, 1 is evidently a Verruca of the 

 Italian Tertiary, which has not been noticed by any subsequent 

 author, to my knowledge. 



VERRUCA STROMIA (O. F. Muller). 



1776. Lcpas stromia O. F. MULLER, Zoologise Danicae Prodromus, p. 251. 



1789. Lcpas stromia MULLER, Zoologica Danica, vol. 3, p. 21, pi. 94, figs. 1, 2, 3, 4. 



1790. Lcpas verruca SPENGLER, Skrivter af Naturhistorie-Selskabet, vol. 1, p. 194. 

 1854. Verruca stromia Muller, DARWIN, Monograph, etc., p. 518, pi. 21, figs. 



la-f (q. v. for synonyms and older references). 

 1897. Verruca stromia Miillcr, WELTNER, Verzeichnis der bisher beschriebenen 



recenten Cirripedienartcn, Archiv f. Naturg., vol. 1, p. 274. 

 1900. Verruca slroemia Muller, WELTNER, Fauna Arctica, vol. 1, pp. 298, 303-4 



(entrance to White Sea). 



Type-locality. North. Sea. 



Distribution. Shores of northern Europe north to Iceland and 

 Greenland, south to England and Helgoland; low tide to 90 fathoms. 

 Pliocene and Pleistocene of Great Britain; ?Rcd Sea. 



Specimens in. the United States National Museum are from Scar- 

 borough, on Pecten, Exmouth, south Devon, on sandstone, with 

 Balanus spongicola, and the Irish Channel, on CJirysodomus antiguus 

 and Balanus liameri, all from the Jeffreys collection. There arc 

 also numerous examples without definite locality, and one lot from 

 the British Crag, Jeffreys collection. I have looked over a good 

 many shells and barnacles from Greenland without finding Verruca. 



This common European species is light brown, much depressed, 

 with the walls broadly spreading; rostrum is much the largest plate. 

 Movable scutum and tergum are very small, especially the scutum, 

 both having three articular ribs. The sculpture of fine, crowded 

 growth lines, is quite unlike any deep-water species. Carina, ros- 

 trum, and fixed scutum interlock by many subequal ribs, but the 

 suture between fixed scutum and tergum is straight and linear. 

 Inside there is a very large adductor ridge or myophore, in form of a 

 flat, downwardly sloping plate in the fixed scutum. In the fixed ter- 

 gum there is a similar plate. Sometimes these plates stand almost 

 vertically, partitioning off the cavities of fixed scutum and tergum. 

 Often the apex of the rostrum also is excavated. The contour is 

 rounded when the barnacle stands alone, but they are often crowded, 

 like Balani, producing curious irregularities of shape. Well-grown 

 English examples measure about 8 or 9 mm. in greatest diameter 

 and 2 to 3 mm. high. 



According to Darwin the rami of cirrus i are slightly unequal. In 

 cirrus ii the posterior ramus is more than twice as long as the anterior. 

 Cirrus iii is like ii. Terminal appendages are two-thirds to four- 



1 Di alcuni Balanidi appartenenti al Regno dl Napoli, m Atti Accad. Sci. Napoli, vol. 5, pt. 2, 1843, 

 p. 117, pi. 1, figs. 4, 5, 6, republished as Crcusia monslruosa Costa, Fauna del Regnl Napoli, Cirropedi 

 p. 2S. 



