N011TH AMKRH'AX KAItLV TKRTIARY BUYOXOA. 795 



FIG. 256. Anatomy of the family Horneridae Gregory, 1899. 



A-L. Horncid lichenoidcs Pontoppidaiu, 1752. A. Section of embryo, X 85. Whether the 

 cilia on the upper part are in two tufts or are continuous is not clear. B. Transverse section of 

 ovicell, X 25. C. Longitudinal section, X 25, showing the polypide and the ovicell, surrounded 

 by the wall (if), from which the reticulum (r) has separated, no doubt in consequence of the 

 processes of preservation and preparation. In the reticulum, on the left-hand side, some ovarian 

 masses are seen. Six embryos are seen in the section. D. Section of protoplasmic reticulum con- 

 taining ovarian masses, X 450. This reticulum is shown slightly magnified in fig. O. B. Section 

 of the wall of the ovicell, X 100. P. Section of the wall of the ovicell, X 250. G. Zoarium, 

 natural size. H-J. Ovicells, X 15, with lateral oeciostome (ot:)- K. Dorsal of a zoarium, X 15. 

 The ovicell is broken and shows the interior of the oeciopore (oep). L. Frontal, X 15. (After 

 Waters, 1903, and Smitt, 1867.) 



M. Hornera concatenate! Keuss, 1869. Longitudinal section, X 12, showing terminal closure. 

 (After Waters, 1884.) 



N, O. Hornera fissurata Busk, 1884. N. Dorsal surface (growing end), X 25. O. Section 

 of zooecial tubes, X 85, showing interior projections. (After Waters, 1888.) 



P. Hornera antarctica Waters, 1904. Longitudinal section, X 25. ( F, frontal and D, dor- 

 sal.) The scaly and lamellar structure is quite visible. The vacuoles (v) perforate the zoarium. 

 The tubes (t) grow and bud as in the other Cyclostomata ; they do not issue from a central 

 canal as Hennig has incorrectly represented. 



Q. Transversal section, X 25. All the polygonal tubes are approximately equal. 



R, S. Frontal and dorsal, X 20, indicating the terminology peculiar to this family. (After 

 Hoimig, 1910.) 



T. Hornera jacksonica, new species. Interior, X 12, showing that there Is no sagittal canal. 



