Correspondence — Br. R. H. Traquair. 235 



COBBESPOITDEUGE. 



OX THE SUPPOSED PECTOEAL LIMB IN COCCOSTEUS DECIPIENS. 



Sir, — Permit me a few words in reply to Prof. v. Koenen's most 

 courteous remonstrance concerning the supposed pectoral limb in 

 Coccosteus. 



Although I did indeed suggest that Prof. v. Koenen may have 

 mistaken the outer margin of the interlateral plate in his C. McJcensis 

 for a pectoral spine, I did so without dogmatism ; and when I have 

 the opportunity of examining the German specimens, I shall do so 

 with a mind perfectly open to conviction. 



But I stand firm as regards the position which I have taken up 

 as regards the absence of any such " Ruderorgan " in Coccostevs 

 decipiens, the type of the genus ; and I do not think that the argu- 

 ment upon which Prof. v. Koenen bases his expectations of its 

 ultimate discovery in this species, carries any weight whatever. 

 When we take into account the position in the head of the sclerotic 

 ring, its delicac}^, and the manner in which the Scotch specimens are 

 crushed, it is by no means astonishing that this structure should be 

 so rarely observable in Coccosteus decipiens. Far otherwise would 

 be the case with a pectoral limb, were such a thing present, — for it 

 is simply incredible that a long stout prominent external appendage, 

 like the "Ruderorgan" in Prof. v. Koenen's restored figure, should 

 have escaped preservation in the hundreds and hundreds of speci- 

 mens of Scotch Coccosteus, which are to be found in the museums of 

 this country, many of which are absolutely entire from the tip of 

 the snout to the point of the tail. 



I cannot therefore share Prof. v. Koenen's expectations as to the 

 future discovery of a pectoral limb in Coccosteus decipiens, and con- 

 sequently must still maintain that if such a limb is really present in 

 C. Biclcensis, v. Koenen, that species must be removed to a new genus. 

 1th April, 1890. R. H. TraQUAIR. 



ME. MELLARD READE OX THE PHYSIOGRAPHY OF THE LOWER 



TRIAS. 



Sir, — So kindly is the tone of Mr. Mellard Reade's reply to my 

 criticisms on his explanation of the Physiography of the Lower Trias 

 that it is not without regret that I am compelled to observe that in 

 my opinion he has failed to meet them. His reply, in short, as it 

 seems to me, errs in excess and in defect. In excess, for these 

 reasons : 



(1) I do not " misconceive the facts in speaking of the Bunter 

 generally as a 'conglomerate.'" Mr. Mellard Reade has misunder- 

 stood my words by isolating my last paper from all that I have 

 previously written. I have touched upon the anomaly of the Lanca- 

 shire Bunter (of what I know something) twice at least (Geol. Mag. 

 Dec. II. Yol. X. p. 204 : Address to Sect. C, British Association, 

 Birmingham, 1886). I did not again mention it, because I had 

 nothing to add to my previous remarks. In reading the proof the 



