363 



and Brachiopods, 1895, p. 222, fig. 127, of C . tigris, Linne, 

 shows no secondary cusps on the marginals. 



RHIPIDOGLOSSA. 



Megatebennus concatenattjs, Crosse and Fischer. 



PI. xix., No. 3. 



Dental formula — 36 . The central teeth consist of 

 one broad median tooth with four smaller on each side, the 

 fourth from the centre tooth having a truncated apex. The 

 single lateral is very large, tricuspid, overlapping the centrals. 

 The marginals represented by °c (infinity) in the formula, 

 are in two rows, each of twenty-one very fine long teeth, 

 serrated at their extremities and fixed at their base along one 

 side of a triangular plate, the rows parallel to the side of the 

 radula. This is bilaterally asymmetrical, and the chief 

 characteristic is the huge size of the single lateral. Three 

 specimens of small, medium, and large size had 40, 43, and 

 50 rows of teeth respectively, the number increasing with the 

 growth of the animal, but not proportionally, as does the 

 size of the individual teeth. 



Lucapinella oblonga, Menke. 



PI. xix., No. 9, x 200. 



Dental formula - " ' 6 . — Radula bilaterally asymmet- 

 rical, single ' lateral very large and very few marginals. 

 Central teeth of nearly equal size, the top is more attenuated 

 in the outermost one than in the others, the last two are 

 peculiar in having a small flange which overlaps the next 

 inner tooth near its base. The single lateral large and multi- 

 cuspid. Two rows of marginals, long and serrated at their 

 upper ends, and fixed at their bases along one side of an 

 elongate rhomboidal plate run parallel to the length of the 

 radula : each row has nine teeth. 



Emarginula Candida, H. Adams. 

 PI. xix., No. 4, x 300. 

 Dental formula <x .l.(4.1.4).l. x. Radula small, bilaterally 

 asymmetrical. Median tooth of centrals broad; outermost 

 tooth narrower than the three adjoining it, and with a 

 flange overlapping the next inner tooth near its base. The 

 single lateral, bicuspid, blunt, and larger than the centrals. 

 Marginals, of two rows, each of twelve long fine teeth, ser- 

 rated at the end, with their bases fixed to the side of a plate, 

 through two parallel rows of minute plates, and parallel to 

 the length of the radula. Dr. Paul Fischer (Man. de Conch., 



