118 



BULLETIN 93, UNITED STATES NATIONAL MUSEUM. 



has a double row of simple, conic, erect spinules near the distal sutures 

 of the sixth to thirteenth segments, where it is broken off (fig. 31, 

 twelfth segment.) 



B. spongicola is related to B. trigonus, but differs conspicuously by 

 the longitudinally striate and not pitted scuta, and by lacking pro- 

 jecting teeth on the anterior margins of the segments of the third 

 pair of cirri. There are also many other differences. The walls are 

 smooth in the large series examined, except for some specimens grow- 

 ing on Pecten, which show traces of sculpture acquired from the shell. 



i This can hardly mean the well-known islets off. San Francisco Bay, since there is no other Pacific record 

 for the species. The specimen is small, but quite typical spongicola, except that the number of pores in 

 the rostrum (14) is smaller than usual. 



BALANUS CALIDUS, new species. 



Plate 25, figs. 1-lc. 



1854. Balanus spongicola, var. with the walls slightly folded longitudinally. 

 DARWIN, Monograph, p. 225, pi. 4, fig. Id. 



Type.C&t. No. 48193, U.S.N.M., from Albatross station 2372, lati- 

 tude 23 15 ' 30" north; longitude 85 29' 30" west, 27 fathoms, 

 surface temperature, 64 F., in the Gulf of Mexico southwest of Cape 

 San Bias, western Florida. 



Distribution. West Indies, from St. Vincent to the northern coast 

 of the Gulf of Mexico, 8 to 88 fathoms. 



The barnacle is conic, the parietes rather strongly ribbed; purplish- 

 pink with paler ribs, or sometimes pure white. Radii rather narrow, 

 their summits less oblique than in B. spongicola. Sheath purplish 

 in colored individuals. Interior strongly ribbed near the base, 

 smooth above. Pores in the bases of parietes rather small, numerous, 

 about 22 in the rostrum. Carinorostral diameter 8 mm.; height, 

 4.8 mm. 



Scutum thick, sculptured externally with crowded growth-ridges 

 and radial striae, but the latter are weaker than in B. spongicola. The 

 articular ridge is larger than in spongicola, and ends below in a free 

 point. The adductor ridge is rather strong but short. There is a 

 little pit between its lower end and the tergal margin, as in B. glan- 

 dula. Pit for the depressor muscle is deep and small. 



