586 PEOF. G. B. HOWES ON THE coRACoiD [June 20, 



Edentates alone excepted) either abuts against or is confluent 

 with the scapular element, audits acromion when diiferentiated'. It 

 is thus seen that the same term has been applied to a localized 

 outgrowth of the coracoid element most variable in its differentia- 

 tion, and to a distinct element of invariable relationships. The 

 different usages of the term epicoracoid have been productive of a 

 precisely similar confusion, as I have elsewhere pointed out ^. If, 

 as is most desirable in the progress of anatomical science, distinct 

 substantive names are to be applied to distinct structures, the 

 terms precoracoid and coracoid must in the future be used to 

 distinguish a portion of the ventral half of the shoulder-girdle 

 which is from one which is not related to the clavicle. I'pon 

 this principle the term epicoracoid can only apply to the Mam- 

 malia, and those Auomodontia ^ in which the coracoid is segmented 

 into two perfectly distinct parts which ossify independently. 



In commenting upon my proposal to restrict the term epicoracoid 

 to the element so named by Cuvier in the Monotremes and its 

 serial homologue, and the term precoracoid to the cartilaginous 

 clavicular bar and its representative, Mr. Lydekker remarks that 

 " this emendation, if properly authenticated," he would have been 

 willing to accept. I presume that by " properly authenticated " 

 he means tenable upon the accepted rules of priority in nomencla- 

 ture ? If so, I would ask ^hat would be the outcome of the 

 application of these, with their rigid restrictions, to the terminology 

 of, say, the elements of the carpus and tarsus, or the muscles of 

 the limbs, so variable in both their characters and detailed 

 relationships? Confusion worse confounded, ' progress ' but not 

 scientific advancement, would, I venture to think, ensue. 



Having proposed to reject the term epicoracoid, and to restrict 

 the term coracoid to the element thus left nameless, Mr. Lydekker 

 suggests the term * metacoracoid ' for the Cuvierian coracoid of 

 Monotremes, and the ' coracoid epiphysis ' of the higher mammals 

 which I have claimed as its homologue. I Mould no less gladly 

 accept his proposals than he would my own, but for the following 

 very grave consideration. The observations of Goette and others 

 leave no doubt that the coracoid and epicoracoid of the Mammal 

 on the one hand, and the single so-called coracoid of the Amphibia, 

 living Eeptilia, and Birds, on the other, are derivatives of that 



^ It is interesting to note that Bradyjms tridactijlits, in the adult of which tlie 

 cX^XKle'ispar c.TCcUence attached to the coracoid, is the very inaiiinial in tlie 

 young of which Hoffmann has detected the primary continuity between the pre- 

 coracoid and acromion. (Niederl. Arch. f. Zooh Ed. v. p. 37.) 



- Loc. cit. pp. lOfi, 197. 



3 With the possible exception of the Ichthyosauria and Nothosauria, in 

 accordance with Seeley's recent observations. My friends in tlie ^Natural History 

 Musexim have accorded me the privilege of examining Prof. Seeley's specimens, 

 and I entirely agree that an unossified ventro-dorsal continuation of the 

 Ichthyosaurian coracoid was present in the region in which he believes it to 

 have been. It seems to me, however, that the notion that a separate (distinctly 

 BCgmented) epicoracoid existed must remain in abeyance, until at least its 

 impress shall have been discovered in the matrix. 



