SHIPWORMS OF THE PHILIPPINE ISLANDS BARTSCH 551 



the inward projection of the posterior part of the shell. Pallets un- 

 known. 



Type. — Eoteredo philippinensis Bartsch. 



All the shipworms so far examined have the blade extending from 

 the inside of the umbone. The present form marks an entirely dif- 

 ferent type of departure, for here it is attached to the middle of the 

 shelf formed by the inward projection of the auricle. I deem this 

 sufficiently distinct to merit generic separation. It is unfortunate not 

 to have the pallets of this species, which wo aid at once show to which 

 of the three genera that I have recognized in my monograph the 

 present genus is most nearly related. 



EOTEREDO PHILIPPINENSIS Bartsch 



PHILIPPINE EOTEREDO 



Plate 54, figs. 4-6; plate 57, fig. 7 



1923. Eoteredo philippinensis Bartsch, Proc. Biol. Soc. Wash., vol. 36, pp. 

 98, 99. 



Shell subglobular, yellowish white, with the posterior portion form- 

 ing the merest trace of an auricle on the outside. Umbones eroded 

 even in very young specimens. The anterior part very broad with 

 its anterior portion terminating in a somewhat curved sinus, the edge 

 of which is slightly reflected posteriorly as a thin callus. The rest 

 of the anterior part is marked by dental ridges, which make an even 

 open curve from the anterior margin ventrally, then posteriorly to 

 their posterior termination, where they join with the dental ridges 

 of the posterior median part. Eighty- two of these ridges remain in 

 the type and a good many more must have been eroded at the um- 

 bone. The ridges of this anterior portion are triangular with their 

 free border finely, evenly serrated. The posterior median portion 

 covers two-thirds of the median part, and is marked by dental ridges 

 which join those of the anterior part at right angles. The denticles 

 here are broad and sharply cusped. The median middle portion is 

 about one-eighth the width of the posterior median portion and is 

 marked by curved rough lines of growth. The posterior median 

 portion is about as wide as the middle median portion and marked 

 by feebler continuations of the lines of growth than those that 

 characterize the middle median portion. The posterior part, or au- 

 ricle constitutes a very small projection when viewed from the out- 

 side, the merest indication of a claw, as it were. Interior bluish- 

 white. The junction of the anterior and median portion is marked 

 by a roughened suture. The umbonal and ventral knobs are promi- 

 nent. The erosion of the posterior umbonal region, even in young 

 specimens, forms an opening in this region to the inside which is 

 anteriorly bordered by a strong shelf that extends from the umbone 



