OF THE SPECIES. 81 



other h.and, are more strongly turned downwards ; wlien the animal is rolled up they 

 embrace the caudal shield, so that the latter fits into tlie wide gap between tliem and the 

 raised-up centre. The rings of the back are highly arched, but without peculiarities in 

 other respects. Caudal shield oblong, triangular, the extremity prominent, and projecting 

 considerably beyond the axis ; the latter seven-jointed, and furnished with an indistinct 

 terminal joint ; the sides furnished with elevated, radial protuberances, which are furcated 

 as far as beyond the centi'e. 



Locality. — The clayslate of Angers {Bed. Mus.), Nantes, the Cotentin. Found also at 

 Valognes and Cherbourg ; in the transition limestone of Esthonia, near Revel, and Zarskoe 

 Selo, also in boulders ( Collection at Halle) . 



Remarks. — 1. There is no doubt whatever that Zetfius verrucosus of Pander is identical with 

 Cahjmene Tristam ; the structm-e of the glabella is quite the same. 



2. The caudal shield represented by Schlotheim {ante cit.) probably belongs to this species. 



2. C. Polytoma : Limbo scuti cephalici antico crenato ; tuberculo capitis antice latiori, in apice 

 quadrilobato. Long. 2-3." 



Äp/.— Dalm. Palcead. 37, Tab. I, Fig. 1, a-c. Emmr. Bissert. 38. 2. Milne Edw. 



Crust, iii, 321. 6. L. v. Buch, Bcitr. 4.5. Asapkus Fischeri, Eichwald, Dissert. 



52, § 58. Tab. Ill, Fig. 2, a. b. Calymene frmitiloba, Stschegloff. Amphion 



frontiloha, Pander. Beitr. 139, Tab. IV, Fig. 1 ; Tab. IV, B, Figs. 5, 6, 7 ; Tab. V, 



Figs. 3, ff, h, and 8. 



Cephalic shield less convex than in the preceding species, and the lateral lobes less 

 turned downwards ; the glabella broader towards the anterior part, furnished with two 

 lateral sulcations, dividing it into three lobes, that are broader anteriorly ; between the two 

 anterior lobes there are three radiating furrows directed towards the centre of the head, 

 which separate two smaller central lobes from the external ones. The enlarged border at 

 the anterior margin is divided by eight furrows into nine rather acute notches or teeth, 

 which very readily break oS", and are therefore wanting in many specimens. Eyes of a 

 moderate size, placed in the line of the posterior lateral sulcation, projecting very far 

 outwards, and inclosed by the indented facial line. Beneath them there seems to be 

 another marginal concentric furrow. Body rings strongly arched, rather short. Caudal 

 shield long, trilateral, rather acuminate ; the axis many-jointed (eleven-jointed according to 

 Dalman's figure and Eichwald's enumeration), and reaches almost as far as the end ; the 

 lateral folds probably not furcated (at least the figures indicate no such division). 



Loc. — The red transition limestone of East Gothland and Esthonia ; I have not myself 

 seen a specimen. 



Remark. — The specimen represented by Dalman was deficient in the margin of the head, and so 

 also was that figui-ed by Pander, Table V, B, Fig. 3. The presence of this notched margin, and the 

 somewhat different structure of the glabella, scarcely justify the constitution of a peculiar genus, as 

 suggested by Pander (who, however, seems to think his species different from Dalman's). His 

 enumeration of the body rings (twenty in the body, four in the tail) is erroneous ; Eichwald had 

 already enumerated them correctly. 



3. C. Blumenhacliii : Limbo scuti cephalici antico integro ; tuberculo capitis subquadrilobo antico 

 sive ultimo maxima, penultimo appeudiculato. Long. 1)4-3". Table II, Figs. 1-3. 



Bef. — Ch. Lyttelton, P/til. Trans, vol. xlvi, p. 598, PI. I, II. C. Moktimeh, 



II 



