Notosolenus urceolatus Larsen and Patterson, 1990

Lee, Won Je & Patterson, David J., 2000, Heterotrophic flagellates (Protista) from marine sediments of Botany Bay, Australia, Journal of Natural History 34, pp. 483-562 : 514-516

Notosolenus urceolatus Larsen and Patterson, 1990

(fi gures 12b, 13c -f)

Description. Cell outline broad posteriorly, narrow anteriorly, with a small neck around the fl agellar canal, 11-17 Mm (mostly 13-15 Mm), 7-11 Mm wide. This species has three dorsal keels, two lateral ridges and three fi ne ventral ridges. The right and left ventral ridges extend from the fl agellar canal. The left one curves slightly from the anterior to the posterior and in some cells it forms an arc. The median ridge extends from the small protrusion near the anterior end of the cell. This species has an asymmetric posterior end with a small protrusion. With two fl agella of unequal length; the anterior fl agellum is slightly longer than the cell, and the posterior fl agellum about 0.6-0.8 times the cell length, is recurrent and inserts to the left of the ventral protrusion in the neck. The reservoir lies in the right-hand side of the cell and the nucleus in the left. Glides slowly with the anterior fl agellum directed anteriorly. Common. Description based on observations of 43 cells.

Remarks. Previously reported cell lengths are from 15 to 22 Mm; this species was reported from tropical Australia and Brazil by Larsen and Patterson (1990). Our cells are very similar in general appearance, in cell length, in having three dorsal keels and fi ne ventral ridges. Larsen and Patterson (1990) described a shallow median ventral groove. We have not seen a groove, but this may reflect feeding history. This species is characterized by its shape, longitudinal dorsal keels and fi ne ventral ridges. Notosolenus urceolatus is similar, in having dorsal ridges or keels, to N. chelonides Skuja, 1939 and N. esulcis Larsen, 1987. Notosolenus chelonides differs because it is twice the size and has several dorsal keels; N. esulcis has four shallow dorsal ridges. This species resembles N. papilio Skuja, 1939 in having dorsal keels and ventral ridges, and in cell length, but N. urceolatus is pitcher-shaped while N. papilio is slightly rhombic. There is some similarity with N. canellatus Skuja, 1948, but N. canellatus has one dorsal and one ventral groove. Notosolenu s urceolatus is distinguished from N. hemicircularis Lee and Patterson , n. sp. by its larger size, the absence of a collar and in having three not fi ve dorsal keels.

We note that our cells described here had two different shapes.`Urceolate’ cells which are broader and have more developed neck than the other`ovate’ cells. The urceolate cells are 11-17 Mm long, 7-14 Mm wide and the ovate cells are 13-16 Mm long, 7-9 Mm wide. Lengths of the forms overlap and in both the left ventral ridges curve to form an arc towards the posterior end of the cell.