CONTRIBUTIONS TO PALEONTOLOGY. 39 



one family which in recent times have been established and pro- 

 posed to receive these, are Athyris ( = Spirigera ), Merista 

 ( = Camarium ), Meristella and Charionella ; while the sub- 

 division of the terebratuloid forms in another direction has given 

 Terebratula proper, Terebratulina, Waldheimia, Terebratella, 

 Centronella, Cryptonella, Rensseljeria, &c. 



The first four are of the athyroid type, and have internal spires, 

 as in Spirifer. The shell in all these is fibrous ; and we have^ there- 

 fore, in the external shell, the means of separation from tho^e of the 

 other type. 



In all the latter group Ave find modifications of the internal 

 appendage, called in Terebratula the loop; but in none of them 

 do spires exist. Moreover, in all these the external shell is punctate; 

 and we do not yet know a punctate shell of the external character 

 here indicated, which contains internal spires.* 



The external characters, therefore, of the terebratuloid forms 

 may be made useful in indicating the family relations of the spe- 

 cies, and may prevent us from referring to the Family Spiriferidje 

 those which belong to the Family Terebratulid^. 



In the Thirteenth Report on the State Cabinet, published in 

 1860, I proposed the name Meristella for certain forms which I 

 regarded as separable from Athyris and Merista ; and for the 

 semiplicated forms otherwise of similar external character, I 

 suggested the name Leiorhynchus. At the same time I described, 

 under Terebratula, the following species : T. lincklmil, T. recti- 

 rostra, T. lens and T. planirostra ; under each one, distinctly stating 

 the shell structure to be punctate, which character at that time 

 afi'orded me the principal means of distinguishing these from 

 athyroid species of similar form, as Meristella haskinsi, M. barrisi 

 and M. doris, which, with Atrypa scitula (Fourth District Report) 

 = Meristella scitula, have at a later period been placed by Mr. 

 Billings among the typical forms of his Genus Charionella. 



Having ascertained some farther characters of these punctate 

 terebratuloid shells, I proposed, in the Fourteenth Report on the 

 State Cabinet,! page 102, the name Cryptonella, giving as one 

 of the characters " shell structure finely punctate." I remarked, 

 in a concluding paragraph : 



• The plicated forms of Retzia and Rhynchospira are of course not included in the 

 designation above made. The Nucleospir>e also approach the terebratuloid forms j 

 but these have an area on the ventral valve, and a different hinge structure. 



t Made to the Legislature April 10th. 18G1, and published in July 1861, 



