92 REPORT— 1884. 



8. Aptychopsis, sp. 



In the University Museum at Cambridge is a small discoidal Aply- 

 chopsis (labelled ' A. anatina '), which is subcircular or oblately circular 

 (that is, transversely oval, with a broad elliptical contour). It is rather 

 convex ; the sutural line remains raised along the somewhat depressed 

 surface ; and perhaps the test is now rather broader than at first, but not 

 far from the original size and shape. Concentric parallel lines ornament 

 the surface ; nuchal suture at an angle of about 60° ; the notch occupying 

 about a third of the length of the shield, which was 20 mm. long by 

 26 mm. in width. 



Collected by Mr. Marr, F.G.S., in the Brathny (Lower Coniston) 

 Flags, at Nanny Lane, Troutbeck, Windermere. 



A similar form from Moffat has been figured by Mr. James Dairon in 

 the ' Trans. Geol. Soc. Glasgow,' vol. vii. part 1, 1883, pi. 7, f. 32. 



There is a somewhat similar oblately circular Aptychopsis in the British 

 Museum, from the Gala Group, Gala Hill, Galashiels ; but it is smaller, 

 and has a relatively larger notch. It seems to have been 9 mm. in length 

 (fore and aft), and 12 mm. wide. The slope of the nuchal suture is 

 about 50°, and the notch reaches half-way down the test : this, however, 

 has suffered considerable vertical pressure. 



No Goniatites have been found with any of the above. 

 [N.B. — The new species will receive names when they are figured.] 



XL Peltocaris, Salter, 1863. Dithyrocaris, Salter, 1852, ' Quart. Jour. 

 Geol. Soc' vol. viii. p. 391 ; Ceratiocaris, Salter, 1860, ' Ann. Mag. 

 Nat. Hist.' ser. 3, vol. v. p. 161 ; Peltocaris, Salter, 1863, ' Quai't. 

 Jour. Geol. Soc' vol. xix. p. 87. 



This Phyllopod has a discoidal, round or oval, tripartite shield, with 

 a straight median dorsal suture, and a curved nuchal suture, which, giving 

 way after death more easily than the other, has left in some instances a 

 rounded, elliptical, or semi-oval cephalic notch in the shield. The separate 

 lateral pieces of the test have an inner concave curve meeting the convexity 

 of the outer margin, instead of a straight sloping inner edge as in Apty- 

 chopsis. These two lateral moieties, however, are not so frequently found 

 separate as is the case with Aptychopsis. In some instances a smaller 

 notch appears at the bottom or apex of the curved notch, sometimes with 

 a little escutcheon peculiar to it ; but this feature requires much more 

 attention. The shield is concentrically striate as in Aptychopsis. 



1. Peltocaris aptychoides, Salter, 1852, ' Quart. Jour. Geol. Soc' vol. viii. 

 1852, p. 391, pi. 21, f. 10; this figure shows a specimen oblately circular, 

 and probably squeezed obliquely. 'Ann. Mag. Nat. Hist.' i860, I. c. 



