CYPRICARDELLA. 347 



has to be discarded. Whitfield and deKoninck have both adopted Cypricardella, 

 the latter referring fifteen species to it from the Carboniferous beds of Belgium, 

 four of them being doubtfully placed in this genus. 



In the second volume of the ' Lamellibranchiata of New York ' (op. supra cit.) 

 Hall acknowledges the identity of Microdon and Cypricardella. I am of opinion 

 that Hall's genus Astartella is probably identical with Cypricardella. The species 

 on which this genus was founded, A. vera, possesses all the characters which 

 I regard as diagnostic of Cypricardella. The date of the description of Astartella 

 is 1858, the same year as that of Cypricardella, but I am unable to ascertain which 

 of the two was actually published first. 



It is to be noted that the existence of a posterior lateral tooth was not 

 recognised in either of Hall's genera, but the hinge of Cypricardella is described 

 as follows : — " Hinge characterised by a triangular tooth in each valve, that of 

 the left valve short and situated beneath the beak, with a more elongate pit or 

 groove behind it for the reception of the tooth of the right valve. The right 

 valve has also a triangular pit beneath the beak for the reception of the short 

 tooth in the left valve, and a long triangular fold behind, which is sometimes double. 

 No lateral teeth have been observed, unless the long oblique fold of the right valve 

 be regarded as a lateral tooth." It is just such a character as this that I have 

 described as a lateral tooth, and if the sides of a tooth socket be at all pronounced 

 they immediately become cardinal teeth ; hence I consider that this description of 

 the hinge is practically identical with that which obtains in the Carboniferous shells 

 which I refer to Cypricardella. De Koninck says that the right valve has two 

 teeth separated by a socket for the single tooth of the left valve, and the cardinal 

 border possesses a long straight groove in both valves destined to receive a 

 ligament which is partly external and partly internal. With the fact that a 

 groove is present I am in agreement, but I do not consider that this groove was 

 for the ligament, as the edges of the valves are in contact at the bottom of the 

 escutcheon, and it is difficult to see how a ligament in such a case could be partly 

 external and partly internal. 



Astartella is stated to have two teeth in each valve, the anterior tooth of the 

 right valve being large and strong, and having a longitudinal pit in the summit ; 

 but I am only able to find figures of the hinge in the work (op. supra cit.) with 

 the original description. 



The shells now referred to Cypricardella have been generally classed with 

 Cypricardia by British paleontologists, but the characters of the hinge at once 

 separate them from this genus ; but I think that Hall's genus may be placed in 

 the family Crassitellidse rather than in the family Astartidse, to which Fischer and 

 Beushausen have referred it, though it really possesses characters intermediate 

 between the two genera. 



