SHIFWORMS OF THE PHILIPPINE ISLANDS — BARTSCH 545 



TEREDO (UNGOTEREDO) MATOCOTANA. new species 

 MATOCOT 8HIPWORM 



Plate 53, figs. 8, 9; plate 56, fig. 2; plate 60, figs. 5, 6, 7 



Shell small, anterior margin of the anterior part with a rather 

 strong sinus which has a thin callus that is not reflected. This part 

 is rather broad and bears strong denticulated ridges which take a 

 sudden turn ventrally at the anterior margin and are then reflected 

 across. They are badly eroded; the last seven only are left in good 

 shape and these are separated at their posterior extremity by narrow 

 grooves much less in width than the raised ridges. The anterior median 

 portion is very broad and bears strong dental ridges which are separated 

 by narrow incised lines. These ridges are a little less in width than 

 those on the anterior part. The last eight only remain; the rest are 

 stripped of their denticles. The denticles are doubly eusped, the 

 anterior cusp being about twice as large as the posterior. The mid- 

 dle portion of the median part is rendered decidedly rough by irreg- 

 ular transverse wrinkles. The posterior portion of the middle part 

 is about as wide as the middle portion and is crossed by lines of 

 growth. The posterior part is very narrow and is separated from 

 the posterior median part by a constriction. Interior bluish-white. 

 The junction of the anterior and median part is marked by a raised 

 thread. The posterior part is not differentiated from the median 

 part within. The anterior portion of the middle part appears can- 

 cellated by transmitted light. A long twisted blade extends from 

 under the strong umbonal knob about four-fifths of the distance across 

 the cavity toward the strong ventral knob. The pallets have a 

 rather long stalk which is somewhat roughened. The stalk as well 

 as the basal portion of the expanded part is of pale horn color. Tiie 

 two cups are made up of white calcareous material and are sepa- 

 rated on the outside by a deep broad channel. The inner border of 

 these two cups is slender and somewhat perforated. It seems to be 

 made up of bars which run parallel with the outer margin of the 

 septum. The distal portion of the horn-colored part of the expanded 

 pallet forms a slightly curved entire line. The sinus is in the cal- 

 careous cup wall only. 



The type (Cat. No. 31 293Q, U.S.N. M) was found in a piece of 

 wood dredged at station 52(>6 in 102 to 135 fathoms on mud bottom 

 off Matocot Point, Luzon, by the United States Bureau of Fisheries 

 Steamer Albatross Philippine Expedition. It measures: Height 

 1.1 mm.; length, 1.3 mm.; diameter, 1.2 mm. The pallet measures: 

 Length, 3 mm., of which 1.7 mm. go to the stalk; diameter, 1.5 mm. 



