Correspondence. 135 



GRAPTOLITES OF THE MOFFAT SHALES. 

 To the Editor of the Geological Magazine. 



Sir. — I shall be glad if you will afford me a portion of your 

 space to reply to certain statements advanced by Mr. W. Carrutbers, 

 in bis paper on tbe " Systematic position of tbe Graptolites, and 

 tbeir supposed Ovarian Vesicles," contained in tbe last number of 

 your Journal. In tbe first place, Mr. Carrutbers is of opinion, that 

 tbe attacbment of a supposed ovarian capsule to tbe stipe of Grapto- 

 lites SedgwicHi, as figured by me (Geol. Mag,, Vol. III. PI. XVII. 

 Fig. 3), is a case of mere juxtaposition. It is very possible tbat 

 tbis view may iiltimately be proved to be correct, and one certainly 

 would, a priori, and from analogy, be inclined to believe tbat tbe 

 mucro should constitute tbe organ of attacbment. On tbis point I 

 do not feel justified in expressing any strong opinion ; but I may 

 remark, en passant, tbat I did not state tbat I bad observed tbis 

 apparent connexion in one specimen only. Wbat I did state was, 

 tbat I bad never observed tbis phenomenon except in tbe case of G. 

 Sedgwickii ; and, in point of fact, I have seen it in three specimens 

 of this Graptolite, though never in any other ; and in the two, which 

 I did not figure, the position of the mucro could not be made out. 



It is undoubtedly true tbat in the majority of cases, there are no 

 external indications, or scars, which could have been produced by 

 tbe fall of a capsule. Still there are cases in which marks exist, 

 which are possibly due to this cause. Thus, Hall has described 

 pustuliform elevations at the bases of tbe cellules in Graptoiithus 

 nitidus, and in G. divaricatus, both Didymograpsi ; and I have 

 observed similar pustules, or, in some cases, pits, at the base of the 

 cellule of Didymograpsus anceps, recently described by myself, from 

 the Moffat shales. These may be the cicatrices of ovarian capsules, 

 as vaguely hinted by Hall, but on tbis point I would be understood 

 to express myself merely hypothetically, and with all due caution. 



Then Mr. Carrutbers concludes that the rounded and oval bodies, 

 without an evident external mucro, which occur in numbers along with 

 the perfect mucronate capsules, must have been mistaken by me for 

 specimens of tbe small Brachiopod, the Siphonotreta micula of Mc Coy. 

 On this point I can only say, that I have collected dozens of the 

 Siphonotreta, in various localities in Dumfriesshire, and I have 

 examined a most extensive suite of the rounded bodies in question, 

 in every state of compression and preservation, and I can safely 

 assert, that it is impossible that any paleeontologist, possessed of 

 ordinary powers of observation, should fall into an error so gross. 

 I never met with any case in which there was tbe need of a 

 moment's hesitation, and a careful examination wUl almost always 

 detect the mucro, at some point or other, within the circumference of 

 the capsule, I therefore repeat the assertion, that tbe rounded 

 bodies are simply the bell-shaped mucronate capsules, compressed 

 from above, downwards instead of laterally. In this view, I am 

 fully supported by the authority of Prof. Harkness (than whom no 

 one is more thoroughly acquainted with the Graptolitic rocks of 



