﻿342 DR. L. MOYSEY ON PALjEOXYBIS FROM. THE [Aug. I9IO,. 



Palceoxyris, on the other hand, has existed through a long space 

 of time, having been found in the Lanarkian Series ( = Lower Coal 

 Measures of Scotland), in the Middle Coal Measures of Rochdale,. 

 Dudley, Coalbrookdale, Yorkshire, and Derbyshire. Brongniart 

 described Palceoxyris from the Gres bigarres (Lower Trias); 

 Schimper from the Bhsetic of Bamberg ; and Ettingshausen's 

 specimens, described under the name of Palceobromelia, came from 

 the Wealden of Deister. This genus therefore ranges from the 

 middle of the Carboniferous Period to the lower portion of the 

 Cretaceous ; few genera have enjoyed so long a geological range. 



Affinities. 



As before mentioned, most modern observers are of the opinion 

 that these organisms are the egg-cases of fishes. 



In a recently published monograph on Chimgeroid fishes, l 

 Dr. Bashford Dean, remarking on the difficulty of obtaining full 

 egg-cases of Chimcera colliei by dredging— probably owing to the 

 fact that the eggs were deposited at depths (over 60 fathoms) 

 where dredging was difficult, or in his case impossible, — states that 

 he obtained from Discovery Bay, Puget Sound, a surprisingly large 

 number of spent egg-cases in 6 fathoms of water, which had, 

 presumably, been drifted from greater depths by currents. This 

 fact suggests an explanation for the occurrence of so large a 

 quantity of Palceoxyris in the limited area of Digby Claypit. 



In discussing the fossil Chimseroid egg- cases, that author 

 mentions a capsule of Iscliyodus 2 from the ' Dogger Beds ' (Jurassic) 

 of Germany, which is a typical Chimseroid egg- case, comparable 

 with those of the recent Collorhynchus. He dismisses Fayolia,. 

 Palceoxyris, and ' Sjnrangium ' as too imperfect and badly preserved, 

 stating that they could equally well be the coprolites of fishes with 

 spiral intestinal valves. He makes exception, however, in favour 

 of a recently discovered ' Spirangium ' (op. cit. fig. 13, p. 28) — 

 presumably because it is in a better state of preservation than 

 most of the American examples. On this specimen he makes the 

 following note : 



' Spirangium, H. E. Sauvage (1903), from Lithographic Stone, Lerida, Spain 

 (Jurassic). If this prove a Chimaeroid egg-case, it is remarkable in a feature 

 suggesting the capsule of a Cestraciont — marginal webs arranged in spiral.' 



In a note defining technical terms (op. cit. p. 28) he gives the 

 following description of the capsule of Chimcera colliei : — 



' In Chimcera colliei the parts of the young fish are found to have a definite 



relation to the egg-capsule The capsule can therefore be referred to as 



containing a case lor the embryo, which is always subdivided into snout 

 sheath, trunk sheath, and tail sheath. The case has also a dorsal side, 

 which bears anteriorly an opercular flap, which provides for the ultimate 

 escape of the young ; and a ventral side, which is usually more convex. [Other 

 descriptive terms are] ....opercular ridges, overlapping, form together the 



1 ' Chimaeroid Fishes & their Development ' 1906, p. 8. 



2 Ibid. fig. 14, p. 31 (after Jsekel). 



