"26 Description of Genera and Species. 



made out are from a higher horizon of the Lower Carl^oiiiferous Eocks than those in 

 which the remains of T. robusta were obtained. It is probable that when better 

 preserved specimens of both forms are available they may be seen to belong to distinct 

 species. In the meantime the evidence is not sufficient to show that such is the case. 



Locality. — Calderwood Cementstone Quarry, East Kilbride, Lanarkshire. 



Horizon. — Lower Limestone Group, Scottish Carboniferous Limestone Series. 



Collector. — Andrew Patton. 



Tealliocakis taruasiana sp. nov. PI. III., figs. 13-16. 



Specific Characters. — Small form averaging 20 mm., with smooth integumenis and 

 without longitudinal keels on the area of the cara])aee behind the cervical fold, and only 

 showing traces of ridge keels near the extremities of the body. 



General Description. — This species is characterised by its very delicate and smooth 

 integuments and its generally slender and elegant form. 



The carapace has a distinct V-shaped cervical fold. The rostrum appears to be 

 shorter in proportion than in any other species of the geims. There are traces of the 

 median keel on the rostrum and the gastric protuberance behind it ; but it does not 

 reach the cervical fold. As usual, the broad sternites of the last seven trunk 

 segments are generally shown through the overlying carapace in compressed specimens, 

 the form being usually so fossilised as to show back up, from which it may be inferred 

 that it was somewhat applanated. The eyes are moderately larg^. The antennules 

 show the usual three-jointed peduncle and the two short terminal lashes, the external 

 one beinsj somewhat the lontjer and more massive. The basal scale of the antenna is 

 largely developed and extends beyond the carapace as far as the end of the 

 antennular peduncle. The peduncle of the antenna is (comparatively short, so that 

 the lash usually appears to be bent oft' at about two-thirds of the length of the 

 scale. The palp of the mandible is visible in one specimen (fig. 13), M. SISS'^, but its 

 character is not apparent. The exopodites of seven slender long-jointed legs are 

 shown outside the margin of the carapace on the left side of the creature, and 

 several of them with the proximal joints can be traced within the carapace, but the 

 exopodites, if preserved, do not show without. Some of the joints of limbs are also 

 shown on the right side. 



The tail is constructed much as in T. loudonensis, but with only the transverse 

 strengthening bands and no ridge keel to any of the six segments. That keel occurs, 

 however, on the telson, which is constricted at the usual place and bears accessory 



