Genus TINTINNOPSIS Stein '67.
(Stein '67; Kent '81; Daday '87; Bütschli '88.)
Medium-sized ciliates, inclosed in a chitinous lorica with embedded sand crystals. The form of the house, or lorica, varies greatly. In some cases the mouth opening is wide, giving the lorica a bell form; it may be long and tubular, short and spherical, or variously indented. The animal is attached, as in the closely allied genus [Tintinnus], by a peduncle to the bottom of the lorica. The anterior end of the animal is inclosed by two complete circles of cilia; one, the outer, forming the adoral zone, is composed of thick tentacle-like membranelles, the other consists of shorter cilia within the adoral zone. The mouth leads into a curved œsophagus containing rows of downward-directed cilia (Daday). The entire body is covered with cilia, but as the lorica is always opaque these can be made out only when the animal is induced to leave the house. The only difference between this genus and Tintinnus is the covering of foreign bodies—usually sand crystals. Movement is rapid and restless, and peculiarly vibratory, owing to the apparent awkwardness in moving the house. Salt water.
Tintinnopsis beroidea Stein, var. plagiostoma Daday. Fig. 47.
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Fig. 47.— Tintinnopsis beroidea. [ ENLARGE ] |
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Synonym: Codonella beroidea Entz '84.
The shell is colorless, thimble-shaped, with a broadly rounded posterior end. The body is cylindrical. The internal organs were not observed. Membranelles 24 in number. Length 50µ; greatest diameter 40µ.
Var. compressa Daday '87.
The posterior end of the shell is pointed, the lower third of the shell is swollen, the upper third is uniform in diameter and without oral inflation or depression. Nucleus not seen.
Length 70µ; greatest diameter 48µ.
Tintinnopsis davidoffi Daday. Fig. 48.
The shell is large, elongated, and provided with a considerable spine. The chitin of the shell is covered with silicious particles of diverse size. The internal structures were not observed.
Length of shell and spine 230µ; diameter of the oral aperture 54µ.
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Fig. 48.—Tintinnopsis davidoffi. [ ENLARGE ] |
![[ ENLARGE ]](#4444407870625710864_fig_48.jpg.id-5730039372744990647.wrap-0.html.html){kind=link}
The variations of these species are considerable, and as the internal structures, such as the nucleus, are essential in fixing their systematic position, I place them as above, provisionally, and until further observations can be made.
| Key to families of Hypotrichida. | ||
| a. | Peristome indistinct; cilia on ventral surface uniform and not differentiated into cirri | Family Peritromidæ One genus, *[Peritromus] |
| b. | Peristome more or less indistinct; cilia reduced to a few rows on the ventral surface; anal and frontal cirri present | Family [Oxytrichidæ] |
| c. | Cilia entirely reduced; frontal and anal cirri present or reduced; macronucleus band-formed or spherical | Family [Euplotidæ] |
| d. | Peristome reduced to left edge and does not reach over the anterior margin | Family Aspidiscidæ One genus, *[Aspidisca] |
| * Presence at Woods Hole indicated by asterisk. | ||