76 Miscellaneous. 



the disappearance of the Atlantis. — Comptes Renclus, May 3, 1869, 

 pp. 1040-1042. 



Note on the Structure of the Blastoidea. 

 By E. Billings, F.G.S., Palaeontologist, Canada Geol. Surrey. 



The remains of the Blastoidea have as yet proved to be extremely 

 rare in our Canadian rocks, only five smaU specimens (three of 

 Pentremites and two of Godas^ter) having been collected up to the 

 present time. While studying these with a view to their description, 

 I was led to investigate the structure of the order, especially with 

 regard to the function of the summit openings. On combining the 

 observations of other authors, whose views I shall give in detail in 

 another paper, I find that we have now sufiicient data to establish 

 the following points : — 



1. In the genus Nudeocrinus, Conrad, there are sixteen apertures 

 in the summit. Of these, the large lateral aperture is both mouth 

 and vent. There is no opening in the centre of the apex, where the 

 mouth has hitherto been supposed to have its position. The ten 

 so-called " ovarial orifices " are respiratory apertures. Between 

 each two of these, one of the ambulacral grooves enters to the interior 

 through a small pore, which is a true ovarian orifice. There are thus 

 ten spiracles, five ovarian orifices, and one buccal and anal orifice — 

 in all sixteen. 



2. In Pentremites there are also five ovarian pores, in the same 

 position. The mouth is not in the centre, but in the larger of the 

 five spiracles. 



3. Cadaster has no ambulacral pores in the so-caUed "pseud- 

 ambulacral fields." The striated surfaces in the interradial areas 

 are true Cystidean rhombs of the type of those of the genus Pleuro- 

 cystites. These in Pentremites, Granatocrinus, and Nudeocrinus are 

 situated under the ambulacra, where they constitute the tubular 

 apparatus described by Roemer and others. — Silliman's Amerimn 

 Journal, May 1869. 



Tadpoles of Lissotriton punctatus reproducing the Spedes. 



By M. J. JULLIEN. 



On the 11th of April 1869, the author obtained four tadpoles of 

 Lissotriton punctatus, which he dissected the next day, when he 

 found in two of them not only fuUy developed ovaries, but in the 

 oviducts eggs enveloped in the usual gelatinous layer. The other 

 two were males. The only external differences between the two 

 sexes were that in the females the labia of the cloaca were more 

 developed than in the males, and that the body was shorter in the 

 latter. The two females were as large as adults. 



The testes, which were pretty well developed and fusiform, con- 

 tained mother cells of spermatozoids, but no free spermatozoids. 

 The ovaries formed two fine bunches, and the oviducts contained 

 perfectly developed eggs in both females. 



Subsequently the author obtained two more female tadpoles, which 

 deposited several eggs in the course of a few days, without acquiring 

 the advJt characters. — Gomptes Bendus, April 19, 1869, pp. 938, 939. 



