[burwash] new species OF MARINE INVERTEBRATES 87 



area curves outward somewhat beyond the parts to right and left of it, 

 while the corresponding margin of the brachial valve is recessed to re- 

 ceive the projection. The deltidium and pedicle opening are not well 

 preserved. Along the mesial line from front to rear the pedicle valve 

 has a strongly arcuate profile, which is somewhat less prominent toward 

 the anterior margin than in the umbonal region where there is a median 

 ridge whose rounded summit falls away to the lateral margins in 

 resupinate curves. 



The brachial valve is less prominently arched in the umbonal region 

 than the pedicle and curves from thence resupinately toward both the 

 lateral and anterior margins. 



While a mesial sinus cannot be said to exist, when viewed anteriorly 

 there is a wide but shallow curvature of the anterior margin toward the 

 pedicle valve. 



The shell is largely exfoliated, but the surfaces of both valves 

 appear to have been marked by numerous rather fine radiating strise, 

 and by indistinct concentric lines of growth at much greater intervals. 

 The punctse are arranged in fairly regular rows, those adjoining in a 

 given row closer together than are the adjoining rows. 



The specimen is distinguished from T. skidegatensis (Whiteaves). 

 By (1) its greater proportionate breadth. (2) the more prominent 

 and sharply-rounded postero-lateral angles, and (3) the arrangement 

 of the punctse, which in T. skidegatensis are not closer together along 

 a given row than at right angles to the row. The name is derived 

 from that of the principal island of the Queen Charlotte group. 



Rhynchonella undulata (sp. nov.) 



(Plate III, Figs. 7a, b, c) 



Cf. R. limbata (Schlotheim) — see Davidson, Fossil Brachiopoda, Vol. I, 



Plate XII, fig. 3. 



The outline of this specimen apart from the beaks is transversely 

 elliptical — the major (transverse) axis being 24 mm. Both beaks 

 project posteriorly beyond the ellipse, into which they merge with 

 concave lateral curves. The total length from front to rear is 

 21 «6 mm. The total convexity is 11 mm., of which about 6 mm. is 

 assignable to the pedicle valve and 5 mm. to the brachial. These 

 measurements are those of a cast from which the shell has been al- 

 most completely exfoliated. The beak of the pedicle valve projects 

 about 2 mm. beyond that of the brachial, and has a well-marked 

 cardinal area extending laterally to points about half way from the 

 apex of the beak to the lateral extremities of the shell. Within the 



