219 



looted by Dr. Dawson from rocks of this division on the North Shore 

 of Cumshewa Inlet. Only one specimen of the shell has been seen, 

 which consists of a cast of both valves with most of the test well pre- 

 served on the posterior half of each. As the sculpture of the anterior 

 auricle and that of the median area of the valves is not known, the 

 identification of this specimen with T. Suciensis is somewhat uncertain. 



MARTESIA CARINIPERA, Whiteaves. 



Plate 29, figs. 2 and 2. 

 Martesia carimfera, Whiteaves. 1876. This volume, p. 54, pi. 9, fig. 7. 



Shores of Bear Skin Bay, in Skidegate Inlet : a fine specimen of a 

 colony of the burrows of this species in fossil wood, with several of the 

 shells in situ. 



CORBULA CONCINNA. ^N". Sp.) 



Plate 29, figs. 3 and 3. 



Shell very small, nearly equivalve, the right valve being a little 

 larger than the left, inequilateral, moderately convex, the thickness 

 through the closed valves being a little less than the greatest height : 

 outline transversly subovate, the length as compared with the breadth 

 being about as seven to five. Anterior end short and regularly rounded 

 at the margin in both valves : posterior end about one-third longer 

 than the anterior, narrowing equally towards its termination, which is 

 obliquely truncated and biangular in the left valve and whose upper 

 angle is rounded off in the right. Cardinal margin rounding abruptly 

 downwards in front, straighter and sloping very gently downwards 

 behind : ventral margin convex and evenly rounded anteriorly, 

 straighter and ascending very gradually posteriorly, most prominent 

 a little in advance of the mid-length. Beaks broad and not very pro- 

 minent, incurved, inclined slightly forwards and situated about half- 

 way between the centre of each valve and the farthest extremity of the 

 anterior end. On the left valve a distinct umbonal ridge extends from 

 the beaks to the posterior end of the base, and behind and above this 

 ridge the valve is inflected at an obtuse angle. On the right valve the 

 corresponding umbonal ridge is almost obsolete and the posterior area 

 ill-defined. 



Surface marked with fine, crowded, and rather irregularly disposed 

 concentric ribs. 



Length, seven millimetres ; greatest height, five mm. ; thickness 

 through the closed valves, four mm. 



South side of Alliford Bay, Skidegate Inlet, very abundant and in 

 good condition ; Bear Skin Bay, one specimen. 



