(351TOmin) Tomocerus minor (Lubbock, 1862)
*plumbeus (Linnaeus, 1758) of Lubbock (1873) [not Lubbock (1862)]
*tridentiferus (Tullberg, 1872)
Tomocerus minor (Fig. 1) is an extremely common and widespread species. The spines on the inner side of the dens are tridentate (Figs. 2 and 3), a highly characteristic feature which makes it impossible to confuse with any other species. The body is covered in scales (Fig. 4) and the empodium of the foot is about two-thirds the length of the claw (Fig. 5). The mucro is long and distinctive (Fig. 6 and 7). Despite being called 'minor', this species reaches 4.5 mm in length.
This species turned up from samples collected all over St Helena, alongside Orchesella cincta, almost certainly introduced by accident by European settlers.
Fig. 1: Tomocerus minor of 4 mm in length photographed in a garden in Reading.
Fig. 2: Isolated furca of Tomocerus minor collected from Ballyvaghan in July 1960 by Peter Lawrence.
Fig. 3: Tridentate spines on the dens of Tomocerus minor collected from Cheltenham in February 1944 by J.M. Williams.
Fig. 4: Scales on the body of the same specimen of Tomocerus minor shown in Fig. 3.
Fig. 5: Foot of Tomocerus minor collected from the Devil's Kitchen, N. Wales in January 1934 by W.M. Davies.
Fig. 6 (see also Fig. 7): Mucros at two levels of focus of the same specimen of Tomocerus minor shown in Fig. 5.
Fig. 7 (compare to Fig 6): Mucros at two levels of focus of the same specimen of Tomocerus minor shown in Fig. 5