THE SESSILE BARNACLES. 59 



from tho screw of tlio Challenger whon at St. Vincent, Cape Verdes, 

 on the return voyage. Specimens in tho United States National 

 Museum and those in the Academy of Natural Sciences have no 

 locality data. 



BALANUS TINTINNABULUM OCCATOR Darwin. 

 Plato 11, figs. 1 to le. 



1854. Balnniis tintinnnbulum, var. occator Darwin, Monograph, etc., p. 19G, pi. 



1, fig. h; pi. 2, fig. lb. 

 1900. Balnnns tintinnahulum (Linnaeus), var. occator T>arwin, Boeradaile, Proc. 



Zool. Soc. London, p. 709 (Fiji). 



Tiji^e. — In tho British Museum; locality unknown. 



Distribution. — Indo-Paoific Province: Zamboanga, Mindanao, E. A. 

 Mearns. 



Padii with their summits slightly oblique; parietes smooth, or 

 ribbed, or spinose; very pale bluish-purple, with narrow darker lon- 

 gitudinal lines; sheath, with the internal surface of the rostrum and 

 lateral compartments, dull blue, whilst the corresponding parts of the 

 carina and carinolateral compartments are white. Seuta vntlt small, 

 sharp, hood-formed points, arranged in straight radiating lines. Terga 

 with the spur placed at either its own width, or less than its own width, 

 from the basiscutal angle. Danvin. 



Italics of the foregoing description are mine. The color varies 

 from pale purple to cream color, with white radii, the summit more 

 or less tinged with purple. 



The deflected tergal area of the scutum is rather narrow and is 

 bent very abruptly, the angle between that area and the face of the 

 valve being but little greater than a right angle. The whole valve 

 is narrow(U' than in B. t. tintinnalmlum. The inner face of the scutum 

 is similar to that of B. t. tintinnahulum, the adductor ridge being very 

 weaJdij developed, obsolete in the lower half of the valve. 



Tho longitudinal furrow of the tergum is more or less open, and 

 the spur varies in proximity to tho basiscutal angle, though always 

 nearer than in B. t. tintinnahulum. 



The habitat Fiji has been given for this race, but most specimens 

 iai collections v/ere from ships. A single specimen was in a lot of B. t. 

 zehra collected by Dr. E. A. Mearns at Zamboanga. It has the 

 violaceous coloring on a whitish ground and the narrow ribs of tho oeca- 

 tor from ships, but no spines are developed. The orifice is broad and 

 triangular. Valves typical, the spur of the tergum inserted at half 

 its own width from the basiscutal angle. 



Figures 1, la, \c to 1^ of Plato 11 represent specimens from the bot- 

 tom of a ship reaching Philadelphia, 120 days from Sudders Bay, 

 Java. Other examples (pi. 11, fig. lb) are from a ship arriving in 

 Philadelphia from Ilongkoiig and Java, via India, and associated 

 with B. t. tintinnahulum and B. t. zehra. 



