SPO. STR.] 



PROTOZOA. 



165 



FIG. 122. Strephochetus 

 richmondensis, showing 

 several specimens ou a 

 slab. 



Spongia, Linnaeus. Not American Palse- 

 ozoic. 



inciso-lobata, see 

 Astylospon g i a 

 incisolobata. 

 stellatim-sulcata, 

 see Astylosppn- 

 gia stellatim- 

 sulcata. 



STREPHOCHETUS, 

 Seely, 1885, Am. 

 Jour. Sci. and 

 Arts, 3d ser., 

 vol. 30, p. 355. 

 [Ety. strepho, I 

 twine; ochetos, canal.] A free cal- 

 careous sponge, showing concentric 

 layers composed of minute 

 twining canals. Type S. ocel- 

 latus. 



atratus, Seely, 1885, Am. Jour. 

 Sci. and Arts, vol. 32, p. 32, 

 Black Riv. Gr. 



brainerdi, Seely, 1885, Am. 

 Jour. Sci. and Arts, 3d ser., 

 vol. 32, p. 32, Chazy Gr. 

 ocellatus, Seely, 1885, Am. Jour. 

 Sci. and Arts, vol. 30, p. 357, 

 Chazy Gr. 



richmondensis, S. A. Miller, 

 1882, (Stromatocerium rich- 

 mondense,) Jour. Cin. Soc. 

 Nat. Hist., vol. 5, p. 41, Hud. 

 Riv. Gr. 



STREPTOSOLEN, Ulrich & Everett, 

 (in press, ) Geo. Sur. 111., vol. 8, 

 p. 273. [Ety. streptos, twisted ; 

 solen, a channel.] Obconical, 

 pedunculate ; central oscula 

 having thin walled tubes ex- 

 tending to the base; oscula 

 surrounded with radiating 

 canals, between which there 

 are vertical ones. Type S. obconicus. 

 obconicus, Ulrich & Everett, (in press,) 

 Geo. Sur. 111., vol. 8, p. 274, Trenton Gr. 

 STREPTOSPONGIA, Ulrich, 1889, Am. Geo., vol. 

 3, p. 244. [Ety. slreptos, twisted ; spongia, 

 sponge.] Massive, composed of inter- 

 twining vertical lamellae, separated by 

 tortuous linear interspaces. Type S. 

 labyrinthica. Poorly denned, 

 labyrinthica, Ulrich, 1889, Am. Geo., vol. 



3, p. 244, Hud. Riv. Gr. 

 Strobilospongia, Beecher, 1889, Mem. Pea. 

 Mus., vol. 2, p. 14, syn. for Pattersonia. 

 aurita, see Pattersonia aurita. 

 tuberosa, see Pattersonia tuberosa. 

 STROMATOCERIUM, Hall, 1847, Pal. N. Y., vol. 

 1, p. 48. [Ety. stroma, layer; kerion, 

 honey-comb.] Hemispherical, com- 

 posed of numerous concentric vesicular 

 layers, more or less wrinkled, without 

 the pores that characterize Stromato- 

 pora. Type S. rugosum. 

 richmondense, see Strephochetus richmon- 

 densis. 



rugosum, Hall, 1847, Pal. N. Y., vol. 1, p. 

 48, Birdseye and Black Riv. Gr. 



STROMATOPORA, Goldfuss, 1826, Petref.Germ., 

 p. 22. [Ety. stroma, stratum; poros, 

 pore.] Dimorphous masses or extended 

 sheets composed of delicate calcareous 

 lamine,in successive layers, separated by 

 minute, vertical pillars, dividing the in- 

 terval in to minute subquadrangular cav- 

 ities ; the whole is perforated by canals 

 irregularly disposed and possessed of 

 exhalant apertures. Type S. concentrica. 



csespitosa, Winchell, 1866, Rep. Low. 

 Penin. Mich., p. 91, Ham. Gr. 



compacta, Billings, 1862, Pal. Foss., vol. 1, 



S. 55, Black Riv. Gr. There is some 

 oubt about the reference of this species 

 to this genus. Possibly it is a bryozoan. 

 concentrica, Goldfuss, 1826, Germ. Petref., 



FIG. 123. ^Stromatocerium rugosum. 



p. 22, and Pal. N. Y., vol. 2, p. 136, Ni- 

 agara Gr. 



constellate,, see Coenostroma constellatum. 

 erratica, Hall, 1873, 23d Rep. N. Y. St. 



Mus. Nat. Hist., p. 226, Up. Held. Gr. 

 e x p an sa, 



H all & 



Whi tfield, 



1873, 23d 



Rep. N. Y. 



St. Mus. 



Nat. Hist., 



p. 226,Che- 



mung Gr. 

 g r a n u 1 a ta, 



Nicholson, 



1873, Ann. 



and Mag. 



Nat. Hist., 



4th ser., 



vol. 12, p. ^ 



92, Cornif- FlG 124 _ stromatopora im 



erous Gr. 

 hindii, Nicholson, 1874, Ann. and Mag. Nat. 



Hist., 4th ser., vol. 13, and Pal. Prov. 



of Ont., p. 13, Niagara Gr. 



12 



