188 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



LEPAS INJUDICATA, new species. 



Plate 67, fig. 5. 



This species is based upon a calcareous plate believed to be the 

 scutum of a Lepadid barnacle. It is thin, trapezoidal in outline, the 

 basal border straight, almost equal to the length, and a little con- 

 tracted or narrowly bent in. The tergal extremity is broad and 

 somewhat convex. The occludent margin is almost straight. The 

 surface has the curvature of an ordinary Lepas, such as L. amatifera., 

 and is sculptured with coarse, unequal concentric folds, with, to- 

 wards the growing edges, some rather fine concentric striation. 



The fossil is imperfect at the tergal end, but if restored according 

 to the lines of growth it would be about 25 mm. long ; width 23 mm. 



That the fossil has been correctly interpreted is by no means cer- 

 tain. If Lepadid, as believed, the very obtuse tergal end probably 

 indicates a small, transversely placed tergum, not running between 

 scutum and carina, or perhaps none. Either condition would denote 

 greater specialization than the modern genus Lepas. However this 

 may be, the fossil is specifically recognizable by its form and sculp- 

 ture, and we must await the finding of further material to reveal 

 its nature. 



Locality and geologic occurrence. — The holotype is No. 324448, 

 U.S.N.M. It was found by MacDonald and Vaughan in a section of 

 the bluffs exposed along the Panama Railroad. Relocation, about 

 3,500 feet south of Gatun Railroad Station, in bed No. 6033&, Gatun 

 formation. Miocene series. 



EXPLANATION OF PLATE 67. 



Fig. 1. Balanus glyptopoma Pilsbry. Lateral view of group from Station 5903. 



2. Rostral view of a specimen of B. glyptopona growing on Pecten, Station 



3. Basal view of fig. 1. 



5903, the outer lamina of the wall removed. Length of rostrum 

 16 mm. 

 4. Balanus concavus rariseptatus Pilsbry. Type. 

 5. Lepas injudicata Pilsbry. Type. 



o 



