30 Description of Genera and Species. 



carapaces, with the uiarked serrate median longitudinal keel interrupted only at the 

 cervical fold and produced in front into the long rostrum, serrated lateral keels, and 

 embossed areas of the carapace studded with short conical spines. The known species 

 that would come under this genus are therefore : — 



1. Anthrapakcinon ijrossarti Salter. 



2. .4. dubius (Prestwicli).^ [Apus.] 



3. A. russellianus (Salter). \_Pakmcarabus.'] 



Anthrapal^mon russellianus (J. W. Salter). PI. lY., figs. 1-6. 



1863. Pakrocaralnis nissellianus J. W. Salter, Quart. Journ. Geol. Soc, vol. xix., 



p. 520, figs. 1, 2. 

 1867. Anthrapakemon russellianus H. Woodward, Trans. Geol. Soc. Glas., vol. ii., 



p. 240, pi. iii., fig. 7. 



Since Salter gave his description of this beautiful species in 1861 and again in 

 1863, a great deal of new material has been accumulating which enables organs and 

 structures to be examined that were not preserved in the specimens available at that 

 time. This is chiefly owing to the careful and discriminating collecting of Mr. E. 

 Dunlop, who generously presented specimens of this form to the Geological Survey 

 Collection. Under his guidance Mr. Tait has been enabled to add a further suite of 

 specimens to the Survey Collection, so that with this material, aided by specimens 

 kindly lent by Mr. Dunlop for the purpose, several points in the morphology of this 

 species can now be cleared up which have a wide bearing upon the relationship, not 

 only of the present species but of a whole group of kindred forms, to the recent 

 Schizopod family Lophogastridae. 



General Descriptiini. — The integuments are relatively thin, though firm and 

 chitinous, the prevailing ornamentation being in the form of short, strong conical 

 spines. The body is short and applanated. and the carapace is much wider than the 

 general axis of the body. The general form of the creature is shown in fig. 6, drawn 

 natural size, from a specimen belonging to Mr. E. Dunlop. The tail is somewhat 

 displaced, the first two segments being driven in and hidden under the carapace, 

 whereas during life a portion of the dorsal part of the last trunk segment would be 

 visible when the animal was thus viewed from above. As a consequence of the 



^ Apus diihiiis Pre.stvvicli, (fmin Milne Edwards' note) in Tran.'i. Geol. Soc, 2nfl .ser.. vol. v.. pi. 41, fiir. '.'. 



1840. 



