Miscellaneous. 79 



distribution in Palseozoic strata. Prof. H. Alleyne Nicholson 

 lias sent me an imperfect calcified specimen from rocks of 

 Ordovician age at Craighead, Girvan, Ayrshire ; and from the 

 Silurian at Wange, Isle of Gotland, Prof. G. Lindstrom 

 has forwarded me silicified casts. It also occurs in fragments 

 of limestone of Trenton age (Ordovician) in Northern Illinois, 

 which have been sent to me by Dr. W. R. Head, of Chicago. 

 Some detached tripodal spicules discovered by Mr. J. Wright, 

 F.G.S., of Belfast, in Carboniferous limestones at Sligo, and 

 described and figured by Mr. H. J. Carter *, also appear to 

 me to belong to a sponge of this genus. Its occurrence in 

 Tennessee, New Brunswick, New York, St. Petersburg, and 

 in the Drift of Northern Germany has already been recorded. 



MISCELLANEOUS. 



Description of a neiv Genus of Oymnosomatous Pteropoda. 

 By M. Paul Pelseneee. 

 The author discusses the described genera of Gymnosomatous 

 Pteropoda, of which he rejects ^gle, Oken, and Cirrifer, Pfeifer, as 

 synonymous with Pnenmoderma, Cuv. ; while Cliodita, Q. & G. 

 = Clione, Pall., Eurybia, Hang = II(dopsyche, Bronu, Pneumoder- 

 mopsis, lironYi. = Decciobranc?iiea, Boas, and Triclwcydus, Eschsch., 

 and Trigonius, Busch, are founded upon larval forms. Pelagia, Q. 

 & G,, and Cymodocea, d'Orb., are provisionally rejected as insuffi- 

 ciently characterized. Six genera are accepted by the author, as 

 tabulated below : — ■ 



1. Visceral envelope presenting a specialized 



branchial apparatus 2. 



Visceral envelope presenting no special 

 branchial apparatus 5. 



2. Acetabuliferous buccal appendages 3. 



No acetabuliferous buccal appendages. ... 4. Clionopsis, Trosch, 



3. No posterior branchia 1. Dexiobranchaa, Boas. 



A posterior branchia 4. 



4. Posterior branchia presenting four sym- 



metrical rays 2. Pneumodenna f, Cuv. 



Posterior branchia consisting of a mem- 

 branous ring 3. Spongiobranchcea, d'Orb. 



5. Body elongated, pointed behind 5, Clione, Pall. 



Body ovoid, rounded behind 6. Halopsyche, Bronn. 



These genera are ranged under four families, namely : — 1. Pneu- 

 modermatidae (genera 1-3) ; 2, Clionida3 (genus Clione) ; 3. Halo- 

 psychida; (genus Halopsyche); and 4. Cliouopsidae (for Clionopsis). 



* ' Annals,' ser. 5, vol. vi. p. 212, pi. xiv. figs. 10, 11. 



t Throughout his paper the author has altered Cuvier's name to Pneu- 

 monoderma, a change which is manifestly incorrect. Cuvier's name 

 conveys the idea that the animal breathes by its skin ; the alteration 

 would give it " skin-lungs '' or a " lung-skin " ! 



