84 kepokt— 1884. 



posterior third, notched deeply in front in the fossil state by loss of the 

 rostral portion; more or less truncate, and often indented posteriori}-. 

 This modification of the posterior extremity is regarded by Mr. J. M. 

 Clarke as of only specific value ; but with us it constitutes the difference 

 between Cardiocaris and Diseinocaris, and the indentation leads us to the 

 cleft posterior margin of Dipterocaris. 



1. Cardiocaris Boemeri, H. Woodward, 1882. ' Geo!. Mag.' Dec. 2, 

 vol. ix. p. 386, pi. 9, figs. 1-7. 



Shield long-obovate, slipper-like. Cephalic portion narrow-triangular, 

 about 15 mm. long in a shield 40 mm. long. Good specimen 35 mm. long 

 (about 45 mm. when complete), 20 mm. in greatest breadth. Fragment 

 of larger shield, probably once 65 mm. long and 40 mm. wide. Another 

 may have been 50 mm. broad and 30 mm. wide. Some small (young) 

 forms, one of them not more than 6 mm. long and 4 mm. broad, are also 

 figured. Slope of nuchal suture at about 60°. In one small specimen 

 the cephalic portion is preserved in place (op. cit. p. 387 and f. 5). The 

 presence of this little frontal piece is quite antagonistic to the adaptability 

 of Cardiocaris as an operculum to a Goniatite. 



Upper Devonian oi the Eifel, at Budesheim, between Gerolstein and 

 Priim. 



2. Cardiocaris Upartita, H. Woodward, 1882. ' Geol. Mag.' Dec. 2, 

 vol. ix. pp. 383, 388, pi. 8, figs. 14 and 15. 



One of those (f. 14) is much like C. Boemeri in shape, but is said to 

 have a dorsal sutui'e, in which case it ought to be placed in or near 

 Aptychopsis ; probably, however, the dorsal line was merely the mark of 

 an imperfect fold or break along the middle (as in Mr. Clarke's figure of 

 Spathiocaris Koeneni, ' Neues Jahrb.' 1884 v °l *■ pi- 4, f. 1). The side- 

 margins are rather less convex than in C. Boemeri, and the hinder end, 

 which is indented, is proportionally broader. Complete, it may have been 

 27 mm. long, by 15 mm. wide. Angle of nuchal notch, 60°. 



In shape, f. 15 (which is imperfect posteriorly) differs from f. 14 ; it 

 seems to be more oval, and is certainly more deeply notched in front 

 than f. 14. It was probably 32 mm. long, when complete ; 17 mm. wide. 



Both the specimens were found in the Upper Devonian at Budesheim, 

 between Gerolstein and Priim, in the Eifel. 



3. Cardiocaris Veneris, H. Woodward, 1882. ' Geol. Mag.' 1882, p. 387, 



pi. 8, figs. 8-12. 

 Shield relatively broader and shorter than C. Boemeri, and consider- 

 ably wider in front than behind. The cephalic notch is also relatively 

 broader. Dr. Woodward gives the following measurements : — 



Length (complete), about 30 mm. ; greatest breadth, 23 mm. 



20 „ „ 15 



j> » 1 J » )> 10 



The angle of the slope of the nuchal furrow is uncertain ; it varies in 

 different specimens, according to the result of pressure and disturbance, 

 40° and 45°, 45° & 55°, and 60° and 65°. 



4. Cardiocaris Koeneni (Clarke), 1844. 



Spathiocaris Koeneni, Clarke, ' Neues Jahrb. fiir Min.' &c, 1884, vol. i. 

 p. 182, pi. 4, f. 1. 



