THE BARNACLES IN THE U. S. NATIONAL MUSEUM. 93 



This species was taken at two adjacent stations in the Atlantic with 

 M. rectum. It is closely related to M. carinatum Hoek, from off Cule- 

 bra, off Ascension Island, and from Cuba, in from 390 to 500 fathoms, 

 which has been described by Hoek'^ and by Gruv"e],*3'et the differences 

 between the forms seem too numerous to permit us to unite them 

 specifically. 



2L carinatum has a proportionately narrower capitulum than 2L sub- 

 carinatuDi, three times as long as wide. It is more contracted below; 

 the basal outline is shorter. The valves seem to be smoother. Accord- 

 ing to Hoek, 21. car!natu)ii is ""almost entirely smooth; when seen 

 with a lens there appear tine striae radiating from the umbones," 

 whereas M. subcarinatiun is rather coarsely wrinkled, as well as finely 

 striate. There is not in J/, carinatum. such a distinct ridge from the 

 umbo to the tergo-carinal angle of the scutum. The carina is more 

 curved, and its upper portion more slender in 31. carinatum^ and it is 

 less hollowed out internall}'. The basal internal areas of scutum and 

 carina are also diverse in the two species. Since a number of individ- 

 uals of both forms from several stations have been examined, it would 

 appear that we have to do with two species closely related, yet, so far 

 as present materials show, distinct. 



Subgenus MEGALASMA Hoek. 



MEGALASMA BELLUM (Pilsbry). 



1907. Pircilasmd bellum Pilsbry, Bulletin of the Bureau of Fisheries, XXYI, 

 p. 183, pi. IV, %. 6. 



Localities. — Albatross stations 4081 to 4084, off' the north and north- 

 east coast of Maui, in 202 to 267 fathoms; Station 4088, between Maui 

 and Molokai, and Station 3803, Kaiwi channel, between Molokai and 

 Oahu, in 220 fathoms. Bottom temperature from 46.7° to 51.7° F. 

 These localities are additional to those given in the original account of 

 this species. 



Genus OCTOLASMIS Gray. 



1825. Octolnsinis Gkay, Annals of Philosophy, X, p. 100, for (J. irarwickii. 



1825. Ileptalasmis Leach, MSS. in Gray, Annals of Philosophy, X, j). 100, based 



upon the same species. 

 1851. Dirhelai'ph Darwix, Monograph on the Cirripedia, Lepadidie, p. 115, first 



species mentioned D. orthogonia. 

 1869. ParodoZepas Macdonald, Proc. Zool. Soc, p. 442, for P. neptuni. 

 1894. Trichelaspis Stebbing, Annals and Magazine of Nat. Hist., 6th ser., XIII, 



p. 443, for T. forresti 



Small Lepadidse. with five incompletely calcified valves, or .some- 

 times apparently with three when the terga are not calcified. The 



"Challenger Reports, Zoology, VIII, Cirripedia, p. 44, pi. i, figs. 8-10; pi. ii, fig. 1; 

 pl. VII, fig. 6. 1883. 



''Transactions, Linnean Society of London, VIII, 1901, p. 157, pl. xvii, figs. 9-16. 



