288 BULLETIN 93, UNITED STATES NATIONAL MUSEUM. 



CYLINDROLEPAS DARWINIANA, new species. 



Plate 68, figs. 3-3&. 



Type. 'No. 2057 A.N.S.P. 



Locality. West Indies? embedded in the skin (not the shell) of 

 sea turtles (Robert Swift). 



The barnacle is hexagonal, the carinorostral diameter a little larger 

 than the lateral, of about equal diameter from base to summit; 

 whitish, with fine sculpture of close transverse wrinkles, and on the 

 carina and carinolateral compartments a few low, coarse vertical 

 ribs. The compartments when isolated are square. Their summits 

 are beveled and polished, apparently by wear. A median fold or 

 rilled sulcus is indicated on the polished summit by a small depression 

 filled with the softer and dull substance of the outer layer; and on 

 some compartments a slight, mesial sulcus is visible externally. The 

 radii are represented by narrow sulci; their edges are distinctly 

 septate. The lower edges of the compartments have about three short, 

 vertical, blunt teeth on each side of a larger median tooth, which 

 bends slightly inward, and is homologous with the prop or midrib 

 in typical forms of Platylepas. The sheath is delicately striate 

 transversely, and stops a little short of the basal edges of the com- 

 partments. The scuta are in contact with the terga, and together they 

 stretch from end to end of the orifice. Carinorostral diameter, 4 

 mm. ; lateral diameter, 3.8 mm. ; height, 3 mm. Some individuals 

 are slightly larger, greatest diameter 5.3 mm. 



These barnacles were in the collection of Robert Swift, one time 

 United States consul in St. Thomas. His collection was almost 

 wholly of West Indian mollusks few, if any, from any other region. 

 He also collected West Indian barnacles. It is likely therefore that 

 this species, which had no locality, was found in the West Indies. 

 In any case, the species differs so widely from those described that 

 it should be easily recognized. 



The specimens of Cylindrolepas were embedded in a very hard 

 yellowish substance showing but little structure. Dr. Thomas Bar- 

 bour, of the Museum of Comparative Zoology, to whom I applied, 

 concluded that it is the salt-water cured, sun-dried skin of either a 

 loggerhead or green turtle, probably from between the neck and 

 flippers or around the base of the tail. 



On account of its small size and deep embedment Cylindrolepas 

 is likely to escape notice. It may turn out to be common and widely 

 distributed. 



Genus STOMATOLEPAS Pilsbry. 

 1910. Stomatolepas PILSBRY, American Naturalist, vol. 44, p. 304. 



Wall bowl-shaped, the orifice far larger than the base; compart- 

 ments six, silicate down the middle, with the outer layer composed 

 of imbricating calcareous scales arranged in chevron pattern ; inner 

 layer projecting above, finger-nail like, beyond the outer, its basal 



