Discartemon sykesi (Collinge, 1902)
“This interesting species seems to be very distinct from any previously described. It is perhaps most closely allied to the S. plussensis of de Morgan, which species, however, has a more heliciform shell, and according to the author’s figures (op. cit. pl. v, figs. 1a-c), there is a distinct notch or groove in the upper portion of the aperture. S. sykesi is much more distantly related to S. planus, Fulton, with which it partly agrees in the form of the aperture.” (Collinge, 1902)
“The lectotype is finely striated on the upper and lower side. At the base, close to the umbilicus, the striation is somewhat stronger, so as to appear rib-like. The umbilicus is very wide, about 4 mm. diam. In the aperture there is only one parietal lamella of about 2 mm. length. The parieto-palatal sinus is high and narrow.” (Benthem-Jutting, 1954)
Collinge (1902) original descriptions on Streptaxis sykesi – “Shell dextral, subdiscoidal, depressed, flattened above, concave below, deeply and widely umbilicated, smooth except for faint lines of growth; whorl 5, regularly increasing, aperture somewhat L-shaped, deeply depressed above, armature consisting of one Lamelliform projection, ascending inwards, situated on the columella whorl; peristome thickened and reflected.”
Streptaxis sykesi – “Diam. Maj. 11.5, min. 8.5; alt. 3 millim.” (Collinge, 1902)
Type locality – “Biserat, State of Jalor” (Collinge, 1902)