72 GOELENTEKATA— POEIFERA phylum ii 



and is made up of fibres composed of three-rayed spicules. B. helvetica (Lor.). 

 Aptian ; La Presta, Switzerland. 



Appendix to Sponges. 



Incertae seclis. 

 Family. Receptaculitidae Koemer.i 



This Singular group which ranges througbout the Ordovician, Silurian, 

 and Devonian Systems, consists of globular, cup-, or platter - shaped bodies 

 containing a central cavity, and whose wall is composed of elements arranged 

 in quincunxial order. The substance of the wall is thought by Hinde to have 

 been siliceous ; calcareous according to Kauff ; aragonite according to Gümbel ; 

 calcite or chitinous according to Billings, either aragonite or chitinous in the 

 opinion of Girty. The elements lying on the outer or under side of the wall 

 have been usually described as consisting of small rhomboidal plates having 

 four transverse rays disposed crosswise, and one inwardly directed ray ; but 

 Girty has found evidence that the spicular summit plates are infiltrations of 

 the rhombic pits of the outer surface, and the radial pillars or spicules are 

 infiltrations filling radial tubes. 



The systematic position of these problematic fossils is wholly conjectural. 

 Gümbel assigns them to the calcareous algae (Dadyloporidae), and others to 

 the Foraminifera and Sponges. Hinde has referred them to the HexadinelUda, 

 but the observations of Eauff and Girty as to the original calcareous and 

 chitinous composition of the wall disprove this inference. 



BeceptacuUtes Defrance. Spherical or pyriform bodies, with a central closed 

 cavity. Ordovician to Carbon iferous. Europe, America and Australia. 



Ischadites Murchison (Dictyocrinites Conrad ; Didyocrinus Hall). Conical or 

 ovate bodies, inclosing a central cavity, with a small summit aperture and 

 lacking an inner layer. Ordovician to Devonian; Europe and America. 



Here are also referred Cydocrinus Eichwald ; Pasceolus Billings ; Polygono- 

 sphaerites Eoemer; Cerionites Meek and Worthen ; Lepidolites and Anomalospongia 

 (Anomaloides) Ulrich. 



Range and Distribution of Fossil Sponges. 



The phylogeny of the Myxospongiae, Ceratospongiae and a part of the Silid- 

 spongiae, owing to their perishable Organisation, remains involved in doubt. 



1 Salter, J. TF., CanadianOrganic Remains, Dec. 1, 1859.— Hall, J., Pal. N. Y., vol. i., 1847 ; 

 Geological Report of Wisconsin, 1862 ; Sixteentli Rept. N. Y. State Cabinet Nat. Hist., 1863 ; 

 Twelfth Rept. State Geologist of Indiana, 1883 ; Palaeontology of New York, vol. iii., 1859 ; 

 Eleventh Rept. State Geologist of Indiana, 1882 ; Second Ann. Rep. N. Y. State Geologist, 1883 ; 

 Palaeontology of New York, vol. vi., 1887. — Ulrich, E. 0., Jour. Cincinnati Soc. Nat. Hist., vol. i., 

 1871; vol. ii., 1879. — Owen, D. />., Geol. Report Iowa, Wisconsin and Illinois, 1844; Geol. 

 Survey of Wisconsin, Iowa and Minnesota, 1852. — Billings, E., Palaeozoic Fossils, vol. i., 1865 ; 

 Canadian Naturalist and Geologist, second ser., vol. ii., 1865 — Meek and Worthen, Geol. Survey of 

 Illinois, vol. iii., 1868. — Gümbel, G. W., Abhandl. der k. bayr. Akad. Wissensch., vol. xii., 1875. — 

 Roemer, F., Letliaea Palaeozoica, 1880. — Hinde, G. J., Quart. Jour. Geol. Soc. London, vol. xl., 

 \8M.— James, J. F., Jour. Cincinnati Soc. Nat. Hist., vol. viii., 1885 ; vol. xiv., ISdl.— Walcott, C. 1)., 

 Mon. U. S. Geol. Surv., vol. viii., 1884:.— Whüßeld, R. P., Geology of Wisconsin, vol. iv., 1884.— 

 Rauff, H., Zeitschr. deutsch, geol. Gesellsch., vol. xi., 1888. — Nicholson and Lydekker, Manual of 

 Palaeontology, vol. ii., 1889 — Winchell and Schuchert, Geol. of Minnesota, vol. iii., pt. 1, Pal. 

 1895. — Ulrich, E. 0., ibid., p. 68— Girty, G. //., Fourteentli Ann. Rept. N. Y. State Geologist 

 for 1894, 1895. — Weller, S., Geol. Survey of New Jersey, Rept. on Pal., vol. iii., 1903. 



