THE SESSILE BARNACLES. 59 



from tho screw of the Challenger when at St. Vincent, Cape Vordes, 

 on the return voyage. Specimens in the United States National 

 Museum and those in the Academy of Natural Sciences have no 

 locality data. 



BALANUS TINTINNABULUM OCCATOR Darwin. 



Plate 11, figs. 1 to le. 



1854. Balanus tintinnabulum, var. occator DARWIN, Monograph, etc., p. 19G, pi. 



1, fig. *; pi. 2, fig. 15. 

 1900. Balanus tintinnabulum (Linnaeus), var. occator Darwin, BORRADAILE, Proc. 



Zool. Soc. London, p. 799 (Fiji). 



Type. In the British Museum; locality unknown. 



Distribution. Indo-Pacific Province: Zamboanga, Mindanao, E. A. 

 Mearns. 



Radii 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. Scuta, with small, 

 sliarp, hood-formed points, arranged in straiglit radiating lines. Terga 

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

 from the basiscutal angle. Darwin. 



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 narrower than in B. t. tintinnabulum. The inner face of the scutum 

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

 weakly developed, obsolete in tho lower half of tho valve. 



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

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

 nearer than in B. t. tintinnabulum. 



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

 in collections were from ships. A single specimen was in a lot of B. t. 

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

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

 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 I, la, le to \e of Plate 11 represent specimens from the bot- 

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

 Java. Other examples (pi. 11, fig. 1&) are from a ship arriving in 

 Philadelphia from Hongkong and Java, via India, and associated 

 with B. t. tintinnabulum and B. t. zebra. 



