HEM. — HOM.] 



MOLLUSCOIDA. 



309 



Fig. 487. 



try pa biordo 



Hemi- 



lineata, Billings, 1866, Catal. Sil. Foss. 



Antic, p. 36, Anticosti Gr. 

 lineopora, Billings, 1866, Catal. Sil. Foss. 



Antic, p. 38, Anticosti Gr. 

 nodosa, Billings, 1866, Catal. Sil. Foss. 



Antic, p. 38, Anticosti Gr. 

 spiniformis, Ulrich, 1882, (Arthroclema 



spiniforme,) Jour. Cin. Soc Nat. Hist., 



vol. 5, p. 161, Trenton Gr. 

 striatopora, Billings, 1866, Catal. Sil. Foss. 



Antic, p. 39, Anticosti Gr. 

 strigosa, Billings, 1866, Catal. Sil. Foss. 



Antic, p. 37, Anticosti Gr. 

 tenuis, see Arthrostylus tenuis, 

 varipora, Billings, 1866, Catal. Sil. Foss. 



Antic, p. 40, Anticosti Gr. 



Hemitrypa, Phillips, 1841, 

 Pal. Foss. Cornwall, 

 Devon, and W. Som- 

 erset, p. 27. [Ety. 

 emisos, half ; trupa, per- 

 foration.] Fenestel- 

 loid ; branches con- 

 nected by dissepi- 

 ments ; cell apertures 

 in two ranges, sepa- 

 rated by carinse, which 



are elevated, widened at the summit, 



and connected by scalse, which meet 



midway and coalesce, forming pseudo- 



carinae. Type H. oculata. 

 aspera, TJlrich, (in press). Geo. Sur. 111., 



vol. 8, pi. 57, Keokuk Gr. 

 biordo, Hall, 1887, Pal. N. Y., vol. 6, p. 



149, Up. Held. Gr. 

 bis^rialis, Hall, 1879, 32d Rep. N. Y. St. 



Mus. Nat. Hist., p. 174, Low. Held. Gr. 

 biserialis var. exilis, Hall, 1887, Pal. N. Y., 



vol. 6, p. 57, Low. Held. Gr. 

 columellata, Hall, 1887, Pal. N. Y., vol. 6, 



p. 146, Up. Held. Gr. 

 cribrosa, Hall, 1881, (Fenestella cribrosa,) 



Trans. Alb. Inst., vol. 10, p. 35, Up. 



Held. Gr. 

 dubia, syn. for Loculipora ambigua. 

 favosa, Hall, 1881, Trans. Alb. Inst., vol. 



10, p. 35, and Pal. N, Y., vol. 6, p. 148, 



Up. Held. Gr. 

 nodosa, Ulrich, (in press,) Geo. Sur. 111., 



vol. 8. pi. 57, Keokuk Gr. 

 prima. Hall, syn. for Unitrypa nervia. 

 pateriformis, Ulrich, (in press.) Geo. Sur. 



111., vol. 8, pi. 57, Keokuk Gr. 

 perstriata, Ulrich, (in press,) Geo. Sur. 



111., vol. 8, pi. 57, Keokuk Gr. 

 plumosa, Prout, 1858, (Fenestella plu- 



mosa,) Trans. St. Louis Acad. Sci., vol. 



1, p. 236, Keokuk and Warsaw Gr. 

 proutana, Ulrich, (in press,) Geo. Sur. 



111., vol. 8, pi. 57, proposed instead of 



Fenestella hemitrypa of Prout, Keokuk 



and Warsaw Grs. 

 proutana var. nodulosa, Ulrich, (in press,) 



Geo. Sur. 111., vol. 8, pi. 57, Keokuk Gr. 

 proutana var. vermifera, Ulrich, (in 



press,) Geo. Sur. 111., vol. 8, pi. 57, 



Warsaw Gr. 

 tenera, Ulrich, (in press,) Geo. Sur. 111., 



vol. 8, pi. 44, Hamilton Gr. 



ulrichi, Foerste, 1887, Bull. Denison 

 Univ., vol. 2, p. 152, Clinton Gr. 

 Hernodia, Hall, 1884, Rep. St. Geol., p. 58. 

 [Ety. hernodes, like a young sprout.] 

 Bryozoum parasitic, procumbent, in- 

 creasing by gemmation like Aulopora; 

 budding lateral, and for some distance 

 in contact and frequently coalescing 

 with the parent cells. Type H. humi- 

 fusa. 



humifusa, Hall, 1884, Rep. St. Geol., p. 

 58, Ham. Gr. 

 Heterodictya, Nicholson, 1875, Geo. Mag., 

 vol. 2, n. s., p. 33, and Pal. Prov. Ont., 

 p. 79. [Ety. heteros, irregular ; dictyon, 

 net.] The correct orthography is He- 

 terodictyon. Flattened, two-edged 

 frond, with subparallel sides, consisting 

 of two series of cells upon opposite 

 sides of a central membrane ; cells are 

 in longitudinal rows; tabulae present. 

 Type H. gigantea. 



gigantea, Nichol- 

 son, 1875, Geo. 

 Mag., vol. 2, p. 



• 34, and Pal. 

 Prov. Ont., p. 

 79, Subcarbon- 



lferous. FlG 488. — Heterodictya 



Hippothoa, Lam- gigantea. Magnified, 

 ouroux, 1821, 

 Expos method. Not Palaeozoic 



inflata, see Stomatopora inflata. 

 Homotrypa, Ulrich, 1882, Jour. Cin. Soc. 

 Nat. Hist., vol. 5, p. 240. [Ety. homos, 

 similar ; trupa, perforation.] Ramose 

 or subfrondescent ; surface smooth or 

 bearing monticules ; cells, circular, ovate 

 or polygonal, thin- walled; groups of 

 larger-sized cells ; mesopores absent or 

 restricted to the maculae; spiniform 

 tubuli, diaphragms and cystiphragms 

 present. Type H. curvata. 



arbuscula, Ulrich, (in press), Geo. Sur. 

 111., vol. 8, pi. 38, Birdseye Gr. 



curvata, Ulrich, 1882, Jour. Cin. Soc. Nat. 

 Hist, vol. 5, p. 241, Hud. Riv. Gr. 



21 



Fig. 489.— Homotrypa obliqua. Natural size 

 and magnified. 



exilis, Ulrich, 1886, 14th Rep. Geo. Sur. 



Minn., p. 80, Trenton Gr. 

 flabellaris, Ulrich, (in press), Geo. Sur. 



111., vol. 8, pi. 32, Hud. Riv. Gr. 



