472 THE PALEONTOLOGY OF MINNESOTA. 



LKampylopr^inata. 



plates of the dorsal valve do not converge medially and join with the posterior end 

 of the median septum, as in Magellania, but that they probably coalesce with each 

 other; a median septum is not present. Muscular scars undetermined. Shell 

 structure impunctate, distinctly fibrous. 



Named for the veteran paleontologist of the New York survey, whose courtesy 

 has enabled us to enhance greatly the scientific value of this volume. 



Type: Hallina saffordi W. and S. 



Waldheimia bicarinata Angelin, sp., and W. mawii Davidson* of Upper Silurian 

 strata of Gotland and England, in all probability also belong to Hallina. Terebratula 

 melonica Barrandef seems to be another species of this genus. The loops of these 

 three species are like those in Hallina nicolleti and H. saffordi, but we are not posi- 

 tive that all have an impunctate shell structure except W. bicarinata, of which alone 

 we have specimens for comparison, and are unable to detect any punctae in them. 



Hallina is the earliest loop-bearing genus known, and since it is chronotogeneti- 

 cally probably near the stock in which the loop and spire-bearing genera had their 

 origin (the Rhynclionellidce) it is safe to say that its calcareous brachial supports do 

 not pass through any metamorphoses as in the Terebratellidce. The fundamental 

 difference between the familiies Terebratulida- and Terebratellidce is not that the former 

 have short loops and the latter long ones, but that the first develops its various 

 generic types of calcareous brachial supports direct, while in the Terebratellidce the 

 mature form is attained by a series of changes or metamophoses. The value of 

 these differences as characters of first importance for family distinction was first 

 announced by Deslongchamps4 The recent work of Fischer and (Ehlert on antarctic 

 living Terebratellidce emphasizes this difference in the development of the loop-bearing 

 forms still more.|| While Hallina has a long loop, in most respects like mature 

 Magellania, it cannot be associated with the latter for the above given reasons, but 

 must be referred to the family Terebratellidce. Hallina has its nearest relatives in 

 Cryptonella, Hall and Megalanteris (Meganteris), Suess of the Devonian. The former 

 can be distingushed from Hallina by its punctate shell structure and the anomalous 

 band joining the crural plates on the dorsal side, while Megalanteris differs from both 

 in the long anteriorly -directed prongs of the crura. It is upon these three genera 

 that Beecher will establish the subfamily Cryptonellince. 



If the loop-bearing families (Terebratulidce and Terebratellida') had their origin 

 in the Rhynchonellida>, which seems probable since the greater portion of the genera 

 of that family are rostrate in form and with more or less completely developed 



British Silurian Braeh., vol. v, pt. i, p. 76, 1882. 



tSee Hall's illustrations of this species in Sixteenth Rep. State Cab. Nat. Hist., p. 49, 1863. 



t Etudes Critiques sur des Brachiopodes Nouveaux on peu eonnus, fasc. 4, 5, 6, pp. 153 and 161, 1884. 



Mission Scientiflque du Gap Horn, Brachiopodes. Ext. Bull. Soc. d' Hist. Nat. d' Autun, t. v, 1892. 



II We will not enter into further remarks on this point, since Dr. C. E. Beecher has in press a revision of these families. 



