Bryozoa of the Pacific coast of America, Proboscina major, p. 621 |
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NO. 3 OSBURN : EASTERN PACIFIC BRYOZOA CYCLOSTOMATA 621 Again there is but little difference in the nature of the ovicells. The fertile zooecium arises like any other tubule and is narrow at its proximal end, broadens to various degrees in the different species, and terminates in a slightly elevated and more or less terminal ooeciostome. The terminal expansion of the gonozoid misled Canu and Bassler into believing that the enlargement was a part of the peristome, and on this basis they created a genus Peristomoecia which has since been discarded. The genus also has a close relationship to Oncousoecia Canu and Bassler (q. v.), which similarly has simple ovicells of much the same nature, but has a flabellate zoarium. Whatever may be the ultimate disposition of these three groups of species, it seems better for the present to allow them generic status— for convenience in classification if for no better reason! Large numbers of "species" have been created on incomplete material, probably most often on immature specimens. It is practically useless to attempt to identify such specimens since only the mature ones with the characters of the ovicells show specific characters. Proboscina major (Johnston), 1847 Plate 65, fig. 5 Alecto major Johnston, 1847:281. Alecto major, Busk, 1875:24. Stomatopora major, Hincks, 1880:427; 1884:204. Stomatopora major, O'Donoghue, 1923:11. Diaperoecia major, O'Donoghue, 1926:23. Oncousoecia major, Canu and Bassler, 1930:46. The zoarium is adnate, strap-shaped, the branches narrow and widening slightly, sometimes a little elevated at the tips on rough substrata. Zooecia in two to four series, the tubules distinct with well-marked grooves, and sometimes in more or less transverse rows; the peristomes moderately high, free, with round apertures. The diameter of the aperture varies greatly, from 0.14 to 0.20 mm and the peristome likewise from 0.20 to 0.26 mm on the same colony. The ovicells are located near the ends of the branches or just proximal to a bifurcation. The narrow proximal end is comparatively short; the middle portion expanded and rather bulbous; the ooeciostome sub- terminal, erect, rather short, smaller than the peristome, its aperture about 0.12 mm in diameter. Usually the inflated area is simple in form, but it may be slightly lobed between the surrounding zooecial peristomes, and occasionally a peristome may be surrounded.
Object Description
Description
Title | Bryozoa of the Pacific coast of America, Proboscina major, p. 621 |
Type | texts |
Format (imt) | image/tiff |
Contributing entity | University of Southern California |
Filename | AHF-PUB-PE-14-03~011.tiff |
Full text | NO. 3 OSBURN : EASTERN PACIFIC BRYOZOA CYCLOSTOMATA 621 Again there is but little difference in the nature of the ovicells. The fertile zooecium arises like any other tubule and is narrow at its proximal end, broadens to various degrees in the different species, and terminates in a slightly elevated and more or less terminal ooeciostome. The terminal expansion of the gonozoid misled Canu and Bassler into believing that the enlargement was a part of the peristome, and on this basis they created a genus Peristomoecia which has since been discarded. The genus also has a close relationship to Oncousoecia Canu and Bassler (q. v.), which similarly has simple ovicells of much the same nature, but has a flabellate zoarium. Whatever may be the ultimate disposition of these three groups of species, it seems better for the present to allow them generic status— for convenience in classification if for no better reason! Large numbers of "species" have been created on incomplete material, probably most often on immature specimens. It is practically useless to attempt to identify such specimens since only the mature ones with the characters of the ovicells show specific characters. Proboscina major (Johnston), 1847 Plate 65, fig. 5 Alecto major Johnston, 1847:281. Alecto major, Busk, 1875:24. Stomatopora major, Hincks, 1880:427; 1884:204. Stomatopora major, O'Donoghue, 1923:11. Diaperoecia major, O'Donoghue, 1926:23. Oncousoecia major, Canu and Bassler, 1930:46. The zoarium is adnate, strap-shaped, the branches narrow and widening slightly, sometimes a little elevated at the tips on rough substrata. Zooecia in two to four series, the tubules distinct with well-marked grooves, and sometimes in more or less transverse rows; the peristomes moderately high, free, with round apertures. The diameter of the aperture varies greatly, from 0.14 to 0.20 mm and the peristome likewise from 0.20 to 0.26 mm on the same colony. The ovicells are located near the ends of the branches or just proximal to a bifurcation. The narrow proximal end is comparatively short; the middle portion expanded and rather bulbous; the ooeciostome sub- terminal, erect, rather short, smaller than the peristome, its aperture about 0.12 mm in diameter. Usually the inflated area is simple in form, but it may be slightly lobed between the surrounding zooecial peristomes, and occasionally a peristome may be surrounded. |
Archival file | hancockunpub_Volume21/AHF-PUB-PE-14-03~011.tiff |