CONTRIBUTIONS TO PALEONTOLOGY. 49 



Fig. 24. Fig. 25. Fig. 26. 



77^ // 



. Fig. 24. Dorsal side of specimen, showing the crural processes directed downwards. 

 Fig. 25. Ventral side of specimen, looking into the dorsal valve. 

 Fig. 26. Profile view of same : the figures twice enlarged. 



This species has been referred to the Grenus Retzia by Mr. Davidson ;* 

 but the specimens which I have examined, have not the character of area 

 or interior structure of any of the typical forms of that genus. t 



MEEISTA AND MERISTELLA. 



In the Thirteenth Report on the State Cabinet, 1860, p. 74, I 

 proposed the Genus Meristella, to embrace certain species before 

 included under the Grenus Merista, and which were shown not to 

 possess the peculiar shoelifter process^ or transverse septum cha- 

 racteristic of the latter genus. I remarked as follows : "Restrict- 

 ing, therefore, the signification of the Genus Merista to such 

 forms as were originally included by Prof. Suess under that name, 

 it becomes necessary to designate those species of similar form, 

 but without the peculiar appendage of the ventral valve, by an- 

 other generic term ; and I would therefore suggest the name of 

 Meristella, proposed by me last year.-'J 



After describing the genus, I cited as illustrations several spe- 

 cies from the Lower Helderberg group, and gave figures of the 

 exterior of Merista pri7iceps and M. nasuta, the latter species from 

 the Upper Helderberg group. 



In the same Report, I described three other species of the genus, 

 viz. Meristella haskinsi^ M. barrisi and M. doris, but without giving 

 illustrations of them. 



Since on the one side this genus has been claimed to be equi- 

 valent to Athyris, and, on the other, the same author has placed 

 some of its species under a later created Genus Charionella, it 



* IntroductiQn a I'Histoire naturelle des Brachiopodes, etc. 1856, p. 103. 



t See Observations on the Genus Retzia, on page 58. 



J In the Twelfth Report on the State Cabinet, 1859, page 78, in referring Atrxjpa 

 naviformis of Yol. ii. Pal.lN.Y., to Merista, I said : " This species, and some others 

 of the Clinton and IS'iagara groups, differ somewhat from true MERiSTiB; and should 

 these diflferences prove of generic importance, I propose for them the name Meri- 

 stella." 



[Senate, No. 115. j J 



