SHIPWORMS OF THE PHILIPPINE ISLANDS BAETSCH 549 



is a strong constriction between the posterior termination of the me- 

 dian part and the posterior auricle. The posterior auricle is large 

 and projects prominently and is marked by a series of ridges that 

 give it a somewhat corrugated appearance. Interior bluish-white. 

 The junction of the anterior and median part is indicated by a 

 strongly impressed straight line. The median part forms a rough- 

 ened area which extends from the umbone to the ventral margin 

 where it terminates in a strong knob. The posterior portion extends 

 over the posterior median portion as a shelf with a shallow cavity 

 behind its anterior edge. This shelf extends from the umbone to the 

 angular junction at the ventral margin of the auricle and the median 

 part. The umbone forms a strong knob from the basal part of 

 which a strong oblique somewhat twisted blade extends toward the 

 ventral knob. Pallets rather long and slender with a narrow spat- 

 ulate calcareous shaft beyond the stalk covered with a brown perio- 

 stracum which terminates distally in a calcareous knob. 



The type (Cat. No. 312917, U.S.N.M.) was collected by the United 

 States Bureau of Fisheries Steamer Albatross Philippine Expedition, 

 from a piece of wood dredged at station 5252 off Linao Point, Gulf 

 of Davao, Mindanao, in 28 fathoms on coral bottom. The type 

 measures: Height, 2 mm.; length, 2 mm.; diameter, 1.8 mm. The 

 pallet measures: Length, 2.6, of which 1.2 go to the stalk; diameter 

 of blade, 0.3 mm. Cat. No. 312918, U.S.N.M., contains an additional 

 lot of specimens from the same piece of wood. Cat. No. 246131-B, 

 U.S.N.M., contains a specimen collected at station 5243 in Pujada 

 Bay, eastern Mindanao, in 218 fathoms on green mud bottom, bottom 

 temperature 63.6°. 



Subgenus Psiloteredo Bartsch 



1922. Psiloteredo Bartsch, Bull. 122, U. S. Nat. Mus., p. 36. 



In this subgenus the auricle fuses with the posterior median por- 

 tion on the inside in such a manner that no shelf projects. In fact, 

 in some of the species it is difficult to note even a suture. The pal- 

 lets are spoon shaped, with the outer distal portion slightly excavated. 



Type. — Teredo dilatata Stimpson. 



7TEREDO (PSILOTEREDO?) ESCARCEOANA, new species 

 ESCARCEO SHIPWORM 



Plate 54, figs. 3, 9; plate 57, fig. 4 



Shell small, semitransluscent, bluish-white. Anterior portion 

 eroded at the umbone, with a narrow callus at that part of the ante- 

 rior margin which is left uneroded. From this slight callus the ridges 

 radiate backward in a fan-shaped manner. At their posterior margin 

 they are about as wide as the spaces that separate them. Of these 



