18 BULLETIN 60, UNITED STATES NATIONAL MUSEUM. 



and about equal. The scutal, upper, and carinal borders are succes- 

 sively longer, the latter nearly twice as long as the rostral. The 

 umbo is nearl}' central. 



The carinal latus is claw-shaped, the umbo projecting below the 

 carina. The basal and lateral margins are about equal, the upper 

 margin very short, the carinal margin concave, with a low, submar- 

 ginal rib. 



The peduncle is covered with large imbricating scales, in about 10 

 rows. 



Length of the capitulum 7, breadth 1 mm. Length of the peduncle 

 2 mm. (Fig. 4.) 



This very distinct little barnacle is related to /S. ^calpellHm^ yet 

 differs in many respects. The capitulum is strongly contracted toward 

 the base, while in 8. .scalpeUum the dorsal and ventral margins are 

 nearly parallel there. The inframedian latus is larger in S. (jihhuni^ 

 with a subcentral, instead of subbasal, mucro. The carinal latus is 

 comparatively longer and narrower than in 8. scalpellum^ and the ros- 

 trum is narrower. Finally, the carina is more strongly sculptured 

 than in 8. scalpelluvi. 



8. (/Ih7feru})i Aurivillius, from off the Rio de La Plata, differs by its 

 smaller rostrum, basal umbo of the inframedian lateral i)late and other 

 characters. 



SCALPELLUM PATAGONICUM Gruvel. 



1900. S. patagoniatiu Gruvel, Bull, du Mas. d'hist. iiat. Paris, 1900, p. 188; 

 Archives du Mns;'um, 4'^ ser., IV, 1902, j). 236, pi. xii, fig. 1a, 16 (coast 

 of Patagonia). 



Localities.— Csii. No. :-]2918, U.S.N.M., Straits of Magellan, Alba- 

 tross Station 2775, in 29.5 fathoms, seated mainly on 2IytHus shells. 

 Station 2776, south latitude 52'^ 11', west longitude 69^ 55' 30", in 21 

 fathoms. Station 2773, south latitude 52° 23', west longitude 68° 11', 

 in 10 fathoms. No. 32917. T.S.N.M., off the east coast of Pata- 

 gonia. Station 2767, south latitude 48° 03', west longitude 58° 56', in 

 52 fathoms. Station 2758, south latitude 42° 24', west longitude 61° 

 38' 30", off the Bay of San Matias, Patagonia. 



Abundant series were taken at Stations 2775 and 2767. In the 

 young and half-grown individuals the chitinous spaces between the 

 plates are nnieh reduced, such examples then resembling 6". scalpel luni 

 (Linnseus). At Station 2775 the typical form occurs, with the capitu- 

 lum 10 to 12 nun. long, and the lunbo of th(> inframedian lateral plate 

 more or less protubei'ant. Similar individuals were taken at Stations 

 2776 and 2773. The largest from the latter station measure 16 mm. 

 long. 



