Three New Species of Teredo 7 
TEREDO (ZOPOTEREDO) JOHNSONI* SP. NOV. 
Plate II, figs, 8-15. 
Shell subglobular, white, covered with a thin, nearly 
transparent, colorless periostracum. The narrow incised 
line separating the anterior and the anterior-median 
areas very slightly curved. The ventral edge of the an- 
terior area meeting the anterior edge of the anterior- 
median area in a nearly straight line, forming an angle 
of approximately 90°. 
Externally, the anterior area large, with many evenly 
spaced, denticulate ridges, which are of about the same 
width as the intervening spaces. There are sixteen of 
these ridges to the millimeter on the posterior-ventral 
portion of this area, each ridge bearing one hundred and 
twenty minute denticles to the millimeter (fig. 8). The 
anterior-median area occupying, at its widest part, one- 
third of the entire median area. The denticulate ridges 
on this area, along a line continuous with the ventral 
edge of the anterior area, average thirty to the milli- 
meter. There are twenty-six of these ridges in the type 
specimen, each ridge bearing approximately thirty-three 
denticles to the millimeter (fig. 9). The middle-median 
area is narrow, divided longitudinally into nearly equal 
halves, the anterior half, with the continuation of the den- 
ticulate ridges, showing as narrow, diagonally descend- 
ing growth lines, which curve upward, and become more 
or less obscure on the posterior half of the middle-median 
area. The posterior-median area large, occupying more 
than half of the entire median area, nearly smooth, show- 
ing only occasional, faint, incised growth lines. The 
auricle very small, being merely a continuation of the 
*I take pleasure in naming this species for Mr. A. A. Johnson, As- 
sistant to the Director of the Marine Piling Investigations Committee 
of the National Research Council. 
