NOTES ON THE BRITISH JURASSIC BRACHIOPODA. 237 



genus in his " Monograph of the Permian Fossils of England," 

 published in the year 1850, dedicating it to a distinguished 

 Russian palseontologist, Fischer de Waldheim (14, p. 145). 



However, the name did not come much into use in this 

 country until after the publication of Thomas Davidson's 

 '' Introduction to the Study of the Brachiopoda " (8). This, 

 perhaps, is not to be wondered at, seeing that only a short 

 time previously Davidson did not altogether approve of the 

 generic separation of Waldheimia from Terehratula, as may 

 be gathered from the following remarks : " The greater or 

 less length of a simply attached loop in Terehratula cannot 

 be made use of as a generic character, especially when there 

 exists no other distinctive points. The length of the loop 

 may be used as sectional, round which we can group certain 

 species ; but who, with any degree of confidence, would place 

 in distinct genera such shells as Ter. cornuta, quadrijida, 

 numismalis, ohovata, digona, ornitJiocephala, etc., which have a 

 simply-attached loop extending to near the frontal margin of 

 the valve, and those such as Ter. punctata, perovalis, maxil- 

 lata, intermedia, sphasroidalis, coarctata, etc., the loop of which, 

 simply attached to the crura, only extends to less than half 

 the length of the valve ? " (7, p. 4). 



Later on Davidson withdrew his objection, and considered 

 that the term Waldheimia might be advantageously preserved 

 for those species possessing a long loop. In the latter 

 portion of his monograph he frequently refers to the well- 

 established genus Waldheimia, King. 



In 1884 Davidson issued his " General Summary to the 

 Brachiopoda," wherein he reviewed the work he and others 

 had accomplished since the year 1850, and in this work he 

 gives his latest classification of the Brachiopoda, so far as 

 the fossil forms are concerned. He placed King's genus 

 Waldheimia in his (Davidson's) sub-family Terebratulidae. 



