MUSEUM OF COMPARATIVE ZOOLOGY. 129 



are abundant reasons for separation if the practice of ]\[r. Smith and other 

 modern naturalists with regard to genera in general be taken as a criterion. 

 Under the Linnean or Lamarckian system they would of course be united ; 

 but with that we have nothing to do. The G. minima was figured by the brothers 

 H. and A. Adams as an example of the genus, and was taken as the type by Sto- 

 liczka, who notes its resemblance to an Astarte (Cret. Pelyc. India). Prof. 

 Adams mentioned no type, but G. cerina was his first species. Other natural- 

 ists have judged the genus by the specimens they happened to possess, or were 

 puzzled if they had representatives of both. However, Carpenter, in 1857, as 

 noted by Smith, pointed out that the Crassatelloid types must be eliminated 

 from Gouldia. In 1853 Morch proposed, without a diagnosis, the genus Lio- 

 concha for shells formerly included under Circe, but inflated and smooth, or 

 concentrically ribbed, and practically identical with Gouldia, as restricted here. 

 The type L. castrensis belonged to the smooth series ; as Stoliczka points out, 

 Lioconcha may be conveniently separated into two sections, in which case 

 Gouldia might be restricted to the concentricalh^ sculptured forms, and Liocon- 

 cha preserved for the smooth ones. If this be thought too refined a distinction, 

 Gouldia, having eight years' priority and a Latin diagnosis, will take pi'ece- 

 dence, and Lioconcha (which has been generally adopted) must be suppressed. 

 The little Crassatella, included with G. cerina by Professor Adams, represents 

 a group, which has been discussed by several writers. Meek among the num- 

 ber, and to which several names have been applied. It is rather numerous in 

 species, and they are very uniform in facies, proportions, and general character. 

 They differ from the typical Crassatella chiefly in form, in the elongation and 

 more distant location of the lateral teeth, their usually unequal valves, and in 

 their uniformly small size. These are not important characters, and the group 

 can at best form but a subordinate section of Crassatella ; yet the preservation 

 of Gabb's name of Eriphyla for the group would not be without a certain 

 convenience. 



A word in regard to the error of combining forms belonging to such different 

 groups may serve to throw a little light on the subject. Prof. Adams' original 

 types of G. -parva were detached valves which had lost their ligament, as also 

 had his (two) specimens of G. cerina. In this condition the cartilage pit pre- 

 serves little trace of its office, and it is really not very easy to point out anv 

 marked difference in the two hinges which, by itself, would separate them 

 more than specifically. The error, with the specimens before one, is really not 

 so surprising as it might seem. 



Goiddia dilecta, as surmised by Mr. Smith, belongs to the typical group ; 

 G. australis I do not know, but there are many more species of various sizes 

 included in collections usually under the name of Lioconcha. 



VOL. IX. — NO. 2. 9 



