PROLECANITES COMPRESSUS. 205 



named " Goniatites discus " by M'Coy, and figured in the " Synopsis," pi. ii, fig. 6, in 

 which, like some other figures in the plates of that work, it has been reverse! 1 by 

 the lithographer, who has also left out the rock in which it is partly embedded. In 

 the figure of the suture-line given by M'Coy (loc. cit.) it is represented as having a 

 divided first lateral lobe, but a careful examination of the specimen shows that such 

 is not the case, but that the first lateral lobe terminates in a single point; and 

 further, that the peripheral lobe is not V-shaped, as M'Coy represents it to be, but 

 is shaped somewhat like the lateral lobes, being slightly contracted above, expanded 

 below, and terminating in a rather acute point. 1 



I may here supply an omission in the diagnosis of the species, and that is 

 that in the adult shell a very conspicuous rim or keel is present at the angles 

 of the periphery on each side. I would further mention the occurrence of 

 " epidermids," seen on the concave impressed zone of the antiperipheral area of the 

 large specimen figured on PI. XLVIII, fig. 4 a (here reduced to about one-half of 

 the natural size), on a part of the body-chamber which, owing to a fracture, can 

 be detached from the specimen. These epidermids consist of short, rather coarse, 

 interrupted, transverse, impressed, wavy lines, which become finer and more pit-like 

 at the ridges bounding the area referred to. The condition of the fossil is such 

 that they cannot be definitely made out on the sides of the body-chamber ; but on 

 the periphery, near its subangular margin, their punctate character can be distinctly 

 seen. 



The features of this interesting species are, I think, well displayed upon the 

 plate, and my only regret is that, owing to want of space, I was obliged to represent 

 fig. 4 a one-half its natural size. Fig. 7 is the suture-line of a specimen from the 

 Isle of Man, and is intended to show the peripheral lobe which is not preserved in 

 the Cork specimen (4 c). The figures of the suture-lines are drawn full size. 



The largest specimen known to me is a fragment which I obtained at Little 

 Island, near Cork ; it is now in the Museum of Science and Art, Dublin ; it has 

 become elliptical by pressure, the longest diameter measuring about 200 nun.; other 

 measurements would be scarcely trustworthy owing to the great distortion of this 

 specimen. A somewhat smaller individual from the same locality, with more marly 

 normal proportions, has a height of body-whorl of 56 mm. at a position probably not 

 far from the aperture. 



Localities. — Cork (city); Little Maud, Blackrock, and Midleton, near the city 

 of Cork; Ballynabointra, county of Cork (Last Riding); "Four miles east of 

 Loughrea," county of Galway. 



1 'Geol. Mag., ' dee. 4, vol. i, Jan., 1894, p. 11: "On the Identity of Ellipsolites compressus, J. 

 Sowerby, with Ammonites Henslowi.J. Sowerby;" b\ A. IT. Foord and (i. C. Crick. 



