186 SYNOPSIS OF THE CHARACTERS OF THE 



but, owing to the state of preservation in whicli those fossils are usually found, it is almost impossible to 

 decide whether they were present or not ; some of the Irish specimens appear to have been attached. 



TURBINOLOPSIS BINA. LonS. ? 

 Turbinolopsis bina. Lons. Sil. Syst. ? — Petraia bina. Lonsd. Geol. Trans Turbinolopsis bina. Phil. Pal. Fos. 



Sjy. Ch. — Conical ; cupi deep ; lamellce about thirty, strongly toothed on the edges, between each pair a very 

 fine slightly elevated ridge, marked with regular, impressed puncta. 



This little species is common in the carb. slate, as well as in the shales of S. Devon, but they appear to 

 me to differ considerably from the Silurian coral of the same name. Length of cast about four lines, width five 

 lines. 



TUEBINOLOPSIS CELTICA. LamouT. 

 Turbinolopsis celtica. PMl. Pal. Foss. 



Sp. Ch. — Elongate, conic; cup deep; lamellae about forty; strongly toothed on the edges. 



This species is common ; it is rather more gradually tapering than the T. bina, and is constantly distin- 

 guished by the greater number of the lamellae ; these are usually forty in the L-ish specimens, but forty-eight 

 according to Phillips, in those from Torquay, while from twenty-four to thirty is the usual number in the 

 T. bina. Length of cast seven lines, width six lines. 



Turbinolopsis pauciradialis. Phil. 



Turbinolopsis pauciradialis. Phil. Pal. Fos. 



Sp. Ch. — Very rapidly expanding, short; lamellae very thin, distant, finely serrated, about twenty in 

 number ; between each pair an obtusely rounded ridge. 



The small number of the lamella3 distinguishes tliis at once from the others of the genus. Length of cast 

 eight lines, width eleven lines. 



& 



Turbinolopsis pluriradialis. Phil. 



Turbinolopsis pluriradialis. Phil. Pal. Fos. 



Sp. Ch. — Obtuse ; aperture expanded ; cup deep ; lamellae about eighty ; between each pair a row of im- 

 pressed puncta. 



The very great number of the lamellae, and consequent narrowness of the intermediate spaces, distin- 

 guishes this species from the others of its genus. Length one inch two lines, width eleven lines. 



TURBINOLIA. 



Ge?i. Ch. — Turbinate, free, base attenuated; star single; internally composed of vertical lamellae and dis- 

 tant, transverse septa. 



TURBINOLIA EXPANSA. M'Co^. (PI. XXVIII. fig. 7). 



Sp. Ch. — Inversely conical, breadth double the height; lamella; about 120, twisted towards the centre. 



A curious and rare species, easily known from the T.funtjites, by the extreme expansion of the disc, which, 

 measured across the star, is usually double the length; the ordinary length of the T.fuwjites is about four 

 inches, measuring, at that length, about one incli across the star ; the present species very rarely attains a length 

 ot one inch and a-half, measuring at that length two inches and three-quarters across the star. I have seen 



