THE SESSILE BARNACLES. 



69 



giving it the same rank as the other races subordinated to B. tintin- 

 nabulum. 



Some specimens in the collection of the Academy of Natural 

 Sciences of Philadelphia, received from Frederick Stearns, are labeled 

 "West coast of Lower California." Part of them are cylindric, with 

 lengthened bases. 



Dar\vin mentions a form of B. tintinndbulum from the coast of 

 Mexico and California which is "rugged and of a dull bluish-purple" 

 color, with "opercular valves exactly like those of var. coccopoma." 

 I have not seen it. 



Localit}-. 



Collector 



Museum. 



Panama, ou oysters 



Panama 



Salinas Bay, Costa Rica 



Bottom of U . S. S. Portsmouth after 



leaving Guaymas, Mexico. 

 Mazatlan, Mexico 



Dr. W. S. W. Ruscheaberger, 



United States Navy. 



Samuel N. Rhoads 



Anasta-sio Alfaro 



Dr. A\'. li. Jones, United States 



Navy. 

 Dr. Paul Bartsch 



Academy of Natural Sciences, 

 Philadelphia. 



Do. 



Do. 

 United States National Museum. 



Do. 



BALANUS TINTINNABULUMCONCINNUS Darwin. 

 Plate IG, fig. 3; plate 17, figs. 5-8. 



1854. Balanus tintinnahulum, var. concinnus Darwin, Monograph, etc., p. 196, 



pi. 1, fig. e; pi. 2, fig. Ig. 

 1903. Balanus tintinnahulum, var. concinnus Gruvel, Nouv. Arcliivesdu Museum 



4 ser., vol. 5, p. 126. 

 1909. Balanus tintinnabulam Liunseus, Pilsbry, Proc. U. S. Nat. Mus., vol. 37, 



p. 65, pi. 16, fig. 3; pi. 18, figs. 5-8. 



Type. — British Museum. 



Distribution. — Straits of Magellan to Peru. 



The barnacle is large, cylindric, or somewhat conic, the orifice 

 usually large. The parietes are nearly smooth or a little roughened, 

 sometimes striate, sometimes weakly plicate ; with many longitudinal 

 lines and waved, transverse, narrow strealcs of livid purple and livid 

 violet on a whitisli ground, producing a finely speckled pattern. Radii 

 broad, with horizontal summits; violet-plumbeous. Alse with nearly 

 horizontal summits. Sheath livid purplish with paler alaj. 



The scutum (pi. 15, fig. 3; pi. 17, figs. 6, 8) has the basi-tergal 

 corner a good deal cut off, the defiectcd tergal segment broad; external 

 growth-ridges rather coarse and prominent; longitudinal strise usually 

 conspicuous. Adductor ridge acute and prominent, broadly overhanging 

 the deep and large pit for the lateral depressor muscle. The rostral 

 depressor pit is often bounded by a small rib. 



The tergum is substantially as in B. t. tintinndbulum, except that it 

 is conspicuously striated longitudinally between the narrow growth- 

 ridges, the striae coarse on the scutal side of the closed furrow, fine on 

 the broader side. Spur separated from the basiscutal angle by twice 

 its own width. 



4729°— Bull. 93—16 6 



