CIRRIPEDES. MOLLUSCA, ANATIFA 21 



Very similar to the preceding. Its angles are everywhere 

 more pointed ; the surface is marked with radiating lines proceed- 

 ing from the anterior-inferior and posterior-superior angles ; this 

 latter angle is at some distance from the summit, and the interven- 

 ing space is often emarginate ; sometimes a range of five or six 

 impressed, blackish dots runs from the angle of the base across the 

 side valves ; the back valve is compressed throughout its whole 

 length, so as to form a sharp edge, which is often more or less 

 toothed. The margins are faintly tipped with orange, but not 

 broadly, as in the last species. The animal is dark-brown, and 

 does not attain to a great length. The cirri are of a dark slate- 

 color. Size same as A. /cms. 



Such are characters of two species of shells, which I found in great 

 numbers and perfection on a Swedish vessel. I believe them to be the 

 true Lepas anatifera and anserifera of Linnaeus. I am not a little in- 

 clined to think that the A. stridta of modern authors is a different spe- 

 cies, of which L. sulcdta of Montagu is the young, and with which L, 

 anserifera is not synonymous. The .difference in the marking of the 

 surface is not very remarkable, but the color of the stem and of the 

 cirri is decisive. The back valve of A. striata is either sharp or 

 broken into teeth, passing imperceptibly into the next species, which 

 is principally characterized by the sharp serratures along the back. 



ANATIFA DENTATA. 



Surface distinctly striated in a radiated manner ; carinated near 

 the anterior margin ; posterior valve compressed to a sharp edge, 

 which is sharply serrate. 



FIGURE 11. 



State Coll., No. 256. Soc. Cab., No. 2085. 



Lepas dentata, WOOD ; Gen. Conch., 67. DILLWYN ; CataL, 32. 



Lepas serrata, SOLANDKR ; Mss. 



Anatifa dentata, BRUG. ; Encyc. Mtth.,63, 1. 166, f. 6. LAM. ; An. sans Vert., v. 676. 



Shell rather shorter and less compressed than the preceding ; 

 the lines of growth and radiating lines are quite distinct ; a very 

 decided angular line or carina passes from the anterior base di- 

 rectly towards the summit, at a little distance from the margin ; 

 the summit is broadly truncated almost directly across ; the dor- 

 sal valve is compressed so as to form a prominent, sharp edge, 

 which at every age presents ten or twelve teeth like those of a 

 saw ; this valve is very distinctly furrowed lengthwise. 



