458 K. ETHERIDGE, JUN., ON A LOWER-CARBONIEEKOTTS PRODUCTUS. 



1850. Prof. W. King figured and described a specimen of Stro- 

 phalosia parva (King)* adhering to the interior of the shell of 

 Productus horridus by means of its umbone and the spines of that 

 part of the shell. Prof. King considered this to be the mode of 

 attachment of all the species of Strophalosia, at least in the young 

 state t. 



1851. Dr. H. G. Bronn^i doubts if the spines were used for the 

 conveyance of water into the shell at all ; for had they done so their 

 distribution over the shell would have been regular and strictly 

 determined. 



1853. Mr. T. Davidson, in his magnificent 'Monograph of the 

 British Fossil Brachiopoda,' passed in review the various speculations 

 which had been advanced on the habits of Productus, and adopted 

 D'Orbigny's view of the function of the proboscis of P. pro- 

 boscideus §. 



1854. The late Dr. S. P. Woodward considered that the Producti 

 may have been attached when young, and that a few species were 

 perhaps permanently fixed. The large spines on the ears of the 

 ventral valve may have served to moor the shell ||. 



1857. Mr. T. Davidson, in a note appended to the description of 

 Strophalosia Goldfussi, Minister ( = S. parva, King?), quotes a 

 remark of Prof, de Koninck's that " sometimes the spines while inter- 

 lacing each other surround foreign objects which may lie within 

 their reach, and that those situated on the beak appear to have pos- 

 sessed that faculty in particular." Specimens, says Mr. Davidson, 

 are in the possession of Prof, de Koninck in which the spines envelop 

 a fragment of the spine of P. Jiorridus %. 



1860. Chevalier d'Eichwald considers that the use of the spines 

 or tubes is unknown ; they are probably simply ornamental. 

 According to his view P. proboscideMS was fixed to rocks by its long 

 tube ; and from this he argues that probably the other species of Pro- 

 ductus were similarly provided with a tube, which was membranous 

 and easily detached from the shell. It is extremely probable that 

 the numerous species of this genus were in general fixed by 

 muscular fibres which issued from the interior of the shell at the 

 lower margin **. 



1862. Dr. J. C. Chenu describes Productus as a free shell ff. 



1868. In the second edition of Dr. S. P. Woodward's valuable 

 work on the Mollusca, by Mr. R. Tate, similar views are expressed 

 to those previously noticed as given in the first edition of the 

 work. 



The evidence contained in the foregoing quotations regarding the 



* Considered by Mr. Davidson to be a synonym of S. Goldfussi, Minister. 



t Mon. Permian Foss. England, p. 95, t. 12. f. 33. 



X Lethasa Geogn. 2nd ed. i. p. 376. 



§ Mon. Brit. Foss. Brach., Introduction, p. 119. 



|| Manual of the Mollusca, 1st ed. pt. 2, p. 234. 



^f Mon. Brit. Permian & Carb. Bi'ach. p. 40, note 1. 



** Lethasa Rossica, i. pp. 885, 886. 



tf Manuel de Oonchyliologie et de Pal. Conchyl. ii. p. 226. 



