352 Br. H. Woochrard — On Helminthochiton — 



From noticing a GomaiiiQ- A'ptyclius in situ, I have quite un- 

 intentionally been led into a lengthened discussion upon Phyllopod 

 shields and the relations of the living Nebalia to the ancient 

 Phyllocarida. 



Some of the results of this paper I may briefly summarize thus : — 



1. I have acknowledged that some of the supposed " Phyllopod- 

 shields " from Budesheim described by me (G-eol. Mag. 1882, 

 Decade 11. Vol. IX. pp. 385-390, PL IX.) are probably AptycM of 

 Goniatifes. 



2. That for others of the described Palaeozoic Phyllopods, alluded 

 to in Prof. T. E. Jones's Keports of 1883-81:, this explanation is 

 inadmissible. 



3. That those which cannot be referred to Aptychi are still, iu 

 all probability, Phyllopods. 



4. That even the Nebalia-Vike forms, now placed in the order 

 Phyllocartda, are certainly not Decapods. And even if they may 

 not with propriety be retained any longer in the old order Phyllo- 

 PODA (of which I am by no means sure), yet they may with more 

 correctness be placed beside them in the Entomostraca, rather than 

 in the Malacostraoa, seeing they have not actually attained to the 

 grade of the latter, but only approached to its larval development ; 

 whilst to the former the adult Nebalia has many very strong points 

 of affinity. 



I cannot conclude these remarks without observing that, whilst 

 deprecating the tone of parts of Herr Dames's criticism of my work 

 as at times too dogmatic for one who has not himself specially 

 studied this group of organisms, and as not calculated to promote 

 friendly feeling between fellow-workers, yet I would express the 

 hope, that, even though we ditFer in opinion, we may still maintain 

 the same good relations as heretofore. 



EXPLANATION OF PLATE IX. Figs. 1-6. 



Fig. 1. Side-view of Goniatites intumescens, Upper Devonian? wiih Aptychus [a) 

 in situ occupying the aperture. 

 ,, 2. View of the mouth of same specimen showing the Aptychus [a) fitting the 



aperture. 

 ,, 3. A detached Aptychvs, ohtained at Bicken, by Prof. Dr. Ferdinand Eoemer, 



and presented by him to Mr. John Edward Lee, F.G.S., of Torquay. 

 „ 4. Another detached Aptychus from the same locality. 

 ,, 5. Ditto. 



,, 6. Ditto. 



All from the Upper Devonian of Bicken near Herbom in Nassau, Germany ; and 

 all drawn of the natural size. 



III. — On a New Species or Helminthochiton from the Upper 

 Bala (Silurian) or Girvan, Ayrshire. 



By Henry "Woodward, LL.D., F.R.S., etc. 



(PLATE IX. Figs. 7-12.) 



My friend Prof. T. Eupert Jones, F.E.S., has lately received 

 several Palasozoic fossils for examination from the rich collec- 

 tion of Mrs. Eobert Gray, of Edinburgh, and has, with the owner's 



