Smyth — Faunal 2iones of Rush-Skerries Carboniferous Section. 555 



Zaphrentia ambigua, var. a. (PI. XXXVI, fig. 7.) 



Lane Limestone, common. 



EusH Conglomerate Series, RlOb&o. 



This variety seems sufficiently distinct to merit notice. It differs from 

 the typical Z. ambigua, Car.,' in the following particulars : — Smaller size ; 

 thicker septa ; counter fossula less exaggerated ; counter septum almost or 

 quite reachiug central mass ; inner ends of septa more or less club-shaped 

 (this is particularly noticeable in the counter septum) ; oai-dinal fossula with 

 sides parallel or, more commonly, slightly convergent inwards, and, at the 

 inner end, rapidly converging to form V-shaped termination ; cardinal 

 septum reduced to a mere tooth ; intermediates scarcely distinguishable. 



Zaphrentis cf. constrkta. Car. (PI. XXXVI, fig. 8). 

 Kate Kocks. 



A transverse section immediately below the calyx shows 23 septa whose 

 radial disposition is striking. In the counter quadrants there is a slight 

 curvature of tlie septa concave to the cardinal region. Tlie cardinal fossula 

 is constricted as in Z. constricta, Car. The cardinal septum is very short. 

 Minor septa rudimentary, but distinct. A counter fossula is present. 



In a lower section the grouping of septa into four groups is notice- 

 able, but their radial arrangement and straightness are still the striking 

 characteristics. A section of the young part has the typical " Omaliusi" 

 structure. 



This coral seems to be closely related to Z. densa, Car., but at no stage 

 are the septa merged in a central mass, the interseptal loculi reaching far in 

 towards the centre. 



Zaphrentis cf. disjuncia, Oar. (PL XXXVI, fig. 1-^.) 

 Rush Conglomerate Series, E. 10. 



This coral shows a very considerable resemblance to Z. dinjuncta, Car. 

 early mut.- The only difference appears to be in the neanie stage, which is 

 exactly as in Z. delanoui, s.s. No " constricta" stage has been observed. The 

 section figured was more than 1.3 mm. below floor of calyx. 



Rush Slates (lowest exposed beds). A single small specimen found at 

 this level may be an early form of the above. 



' Geol. Mag-., 1908, PL iv, fig. 5. The .specimen tigured by Cari'uiher.s is from Horrooksford 

 Quairj', near Clitheroe, which is now ahundantly proved to be not higher than Ci. 

 - Quart. Jouin. GeoL Soc, voL Ixvi (1910), p. 534, ami PI. x.\xvii, fig. 6. 



