TEREBRATULA. 13 



no one would be able to identify a species from that alone, authors have justly agreed 

 to retain Sowerby's name for the shell under description. T. virgoides, M'Coy, does 

 not appear either to Mr. Salter or to myself to present any distinctive characters of 

 sufficient value to warrant its separation from Sowerby's species, as proposed by the 

 Irish author, because it is not uncommon to find that the depression described in T, 

 hastata occurs only in one of the valves, while in other cases it is hardly perceptible in 

 either; the front margin is also very variable, being quite straight, and even slightly 

 convex, in some individuals, while in others it presents many degrees of concavity, so much 

 so that some individuals in this respect resemble T. cornuta, Sowerby. For similar 

 reasons we are doubtful as to the propriety of admitting T. Jicus, M'Coy, established 

 from a single shell in the Cambridge Museum ; but as we have since been able to 

 examine some other examples, more elongated it is true, but otherwise approaching 

 M'Coy's type, and differing by their extreme convexity and non-indented front from the 

 generality of full-grown examples of T. hastata, that it may perhaps appear desirable to 

 provisionally retain for these exceptional forms the varietal denomination of Jicus, given 

 by Professor M'Coy to his species. 



T. hastata was ornamented by stripes, in all probability of a red colour, similar to 

 those we find in several recent forms, such as T. rubella, T. pulchella, &c. They are 

 also very similar to those seen on some specimens of Terebratula biplicata, from the Upper 

 Green-sand of Cambridge, as may be perceived by referring to Vol. I, Part II, pi. vi, fig. 6. 

 T. hastata has been stated to have been found also in the Permian rocks, but I must 

 confess that I have never observed any specimens that would satisfactorily prove the 

 assertion ; nor am I disposed to admit that it and T. elongata did belong to the same 

 species, as it has been more than once hinted. 



Loc. T. hastata abounds in many English and Irish localities, but seems to be a 

 much rarer shell in Scotland. I have it from Derbyshire, and in particular from 

 Park Hill, Longnor, and a beautiful series, with their colour-markings, may be seen 

 in the Museum of Practical Geology. It is common at Lowick, Kendal, Settle, Bolland, 

 the Isle of Man, &c. In Ireland it abounds at Millecent, Lisnapaste, Little Ireland, &c. 

 In Scotland at Nellfield, Lanarkshire. It is not a rare fossil on the Continent. 



YsiY.fcus, M'Coy. Plate I, figs. 13—1.6. 



Seminula ficus, M'Coy. Annals and Mag. of Nat. Hist., vol. x, 2d series ; and 

 British Palaeozoic Fossils, p. 409, pi. iii D, fig. 22, 1855. 



The variety feus is longer than wide, ovate, with convex and gibbous valves, present- 

 ing in old individuals a tendency to become obscurely triundate towards the front. The 

 margin in front forms a convex outward curve, which in the ventral valve is likewise 

 slightly raised, and indents to a lesser or greater degree that of the opposite one. The 



