130 BULLETIN OF THE BUREAU OF FISHERIES. 



is most difficult without long practice" between immature specimens of B. eburneus and 

 the young of B. improvisus. According to both Darwin and Gruvel, the latter species 

 is recorded from Nova Scotia and the coast of the United States, though no definite 

 localities are stated. Thus it does not seem unlikely that this species occurs in our local 

 waters and that it may have hitherto been confused with Balanus eburneus. Barring 

 this possibility, however, of a confusion with some closely similar species which has 

 not been recorded from local waters, it is probable that nearly all of the barnacles 

 dredged by the Survey are to be assigned to Balanus eburneus. Acting upon this suppo- 

 sition, we have plotted out a single distribution chart based not only upon the specimens 

 which have been identified as Balanus eburneus but upon those which, owing to imma- 

 turity or poor preservation, could not be identified with confidence. The two sets 

 of records have, however, been separated in the faunal catalogue. 



The chart (84) shows us that this species is of general occurrence and of considerable 

 abundance throughout both the Sound and the Bay. It was recorded from 157 stations, 

 or somewhat more than one-third of the total number dredged. The specimens which 

 were dredged were commonly attached to stones or shells, very frequently to shells 

 which were occupied by hermit crabs. This last circumstance may account, in some 

 measure, for the very general distribution of this species upon the local sea floor. 

 Balanus eburneus occurs at all depths within our region, even extending up to the 

 neighborhood of the low-water mark, where its zone overlaps that of B. balanoides." 1 



The range of Balanus eburneus, according to Darwin, is from Massachusetts ("about 

 lat. 42 ") to Venezuela and the West Indies. It thus falls within the class of southward- 

 ranging species. 



Barnacles of one (perhaps two) other species were dredged by us. Large specimens 

 of Balanus porcatus were taken at Crab Ledge, and at least one specimen of this same 

 species was taken in Vineyard Sound. Other worn shells, which are believed to be 

 those of either B. porcatus or B. crenatus, were dredged on several occasions in the Sound. 

 The latter species was said by Verrill to be "abundant" in Vineyard Sound, but this is 

 directly contradicted by our own experience, though we have found it growing in 

 considerable numbers upon piles at Vineyard Haven. 



Above low- water mark Balanus balanoides occurs in prodigious profusion, being 

 one of the most abundant and conspicuous members of our littoral fauna. With it 

 upon rocks and piles, though commonly at a somewhat higher level, is to be found 

 Chthamalus stellatus, which is likewise abundant and generally distributed along our 

 shores locally. 



A number of species of stalked barnacles of the genera Lepas and Conchoderma 

 are included in our list. Several of these species, notably Lepas fascicularis , L. hilli, 

 and L. anatifera, are sometimes found in considerable profusion. They are, however, 

 pelagic organisms which find their proper home in the open sea. 



a We have found Balanus balanoides, B. eburneus, B. crenatus, and Chthamalus stellatus growing together on a single piece of 

 bark removed from a wharf pile at Vineyard Haven. 



