200 



BRITISH CARBONIFEROUS BRACHIOPODA. 



without trace of perforations, the testaceous ones are traversed by a multitude of minute 

 canals, recalling those of the Terebratulidse. 1 Mr. S. Cloez has likewise shown that the 

 valves of Lingula, when dried at 100°, contain, for 100 parts — 



Organic matter ...... 45*20 



Carbonate of lime ..... 668 



Phosphate oflime ..... 4229 



— of magnesia ..... 3'85 



— of sesqui-oxide of iron . . . 1*98 

 Silica ....... Traces. 



This distinguished French chemist observes, at the same time, that this composition of 

 the test of Lingula approximates to that which M. Chevreuil signalised in the scales of the 

 Lepidostria, as well as to the test of insects as described some years ago by Hatchett. 



Fig. 1. Fig. 2. 



Lingula unatiaa (recent). 

 Fig. 1. Ventral valve, Woodward, Hancock, &c. ; valve superieure, Gratiolet. 

 Fig. 2. Dorsal valve, Woodward, Hancock, &c. ; valve inferieure, Gratiolet. 

 Posterior occlusor, Hancock ; = anterior adductors, Woodward ; = pre-adducteurs, Gratiolet ; = untere schiese 



muskelbiindel, Vogt ; as muscles qui vont directeracnt d'une coquille a l'autre, Cuvier. 

 Anterior occlusor, Hancock ;== anterior retractors, Woodward ; = muscles obliques postero-anterieurs, Gratiolet; 

 = mittlere schiese muskelbiindel, Vogt. 

 •. Divaricator, Hancock ; = posterior adductor, Woodward ; = post-adductenrs, Gratiolet ; = oberer schliessmuskel, 

 Vogt. 

 Posterior adjustor, Hancock ; = posterior retractors, Woodward; = muscles croiso ou oblique transverse, 



Gratiolet. 

 External adjustor, Hancock ; = external protractors, Woodward ; = surface sur laquelle se prolonge l'insertion 



du muscle oblique antero-posteiieur paire externe, Gratiolet. 

 and c',p'. Central adjustor, Hancock; = central protractor, Woodward, c, p. Muscles obliques auterieurs 



paire interne, Gratiolet ; and c', p', muscles obliques anterieurs paire interne et externe, Gratiolet. 

 Line indicating the posterior parietals, Hancock ; = peaussier verticaux, Gratiolet. 



Peduncular muscle, Hancock ; = capsule of pedicle, Woodward ; = muscle interieur du pedoncule, Gratiolet. 

 i. Impressions produced by the central branches of sinuses, Hancock. 

 s. Impressions produced by the outer or lateral branches of sinuses. 

 v. Impressions produced by pallial lobe. 



' I have considered it desirable to reproduce these details, as they are important to British Palaeonto- 

 logists, and have been taken from the first portion of Dr. Gratiolet's recently published memoir on 'The 

 Anatomy of Lingula anatina ;' and I avail myself of the present opportunity to express my grateful 



p, a. 



a, a. 



P,P- 

 e,p. 



c,p, 

 x. 



