1B9 



CORYPHODON. 



CORYSTES. 



170 



between two tiers of scales, which form a protection, and probably 

 give strength to the basal portion of the fin-rays. These fins extend 

 the whole length of the body ; the head and teeth are nearly the 

 same as in the true Coryphmtce ; the scales are large. 



P. ocellat us (Cuv ) is about 4 inches in length, and of a silvery hue ; 

 the pectoral and caudal fins are yellowish ; the others are bluish-gray, 

 and the dorsal fin has a large blue spot near its highest part. 



rterattts ocellatui. 



CORYPHODON, a genus of Fossil Animals belonging to the family 

 of Tapirs. The remains of this genus have been found in this 

 country ; and although closely allied to the genus Lophiodon of Cuvier, 

 Professor Owen regards its differences as of sufficient importance to 

 constitute a new type. The specimen on which this genus was esta- 

 blished is unique, and was dredged up from the bottom of the sea 

 between St. Osyth and Harwich on the Essex coast, and now forms 

 part of the collection of John Brown, Esq., of Han way Green, near 

 Colchester. This specimen is petrified, containing metallic salts, and 

 having the appearance of fossils from the London Clay. There can be 

 little doubt that it was originally imbedded in the Eocene Tertiary 

 Formation of the Harwich coast. It consists of the right branch of 

 the lower jaw, containing the last and part of the penultimate molar 

 teeth of the lower jaw. Although this fragment resembles the same 

 bone in the genus Lophiodon, yet a close examination of the crown of 

 the last molar tooth exhibits a smaller antero-posterior diameter in 

 proportion to its transverse diameter, as compared with the corre- 

 sponding tooth in that genus. It also differs from the teeth of 

 Anthracotherium, to which it has some resemblance. Professor Owen 

 infers from this and other characters of these teeth that " the whole 

 dental series of the extinct Eocene Pachyderms offered modifications 

 of the Lophiodont type of dentition, which led towards that of the 

 A nthracotherimn, more especially of the smaller species from Garonne 

 and Valery. From the closer resemblance which the fossil presents 

 to the true Lophiodons, it must be regarded as a member of the same 

 family of Tapiroid Pachyderms; indicating therein a distinct sub- 

 genus, characterised by the want of parallelism of the two principal 

 transverse ridges, and by the rudimental state of the posterior talon 

 in the last molar tooth of the lower jaw. The name Coryphodon, which 

 I have proposed for this sub-genus, is derived from \opu<^, a point, 

 and oSoiii, a tooth ; and is significative of the development of the 

 ridges into points. The broad ridged and pointed grinding surface of 

 the tooth indicates its adaptation to comminute the coarser kinds of 

 vegetable substances ; and it is very probable that the habits and 

 food of the Tapir, which is the nearest existing analogue of the Cory- 

 phodon, are not very dissimilar from those which characterised of old 

 the present extinct species and the true Lophiodons." 



Professor Owen gives the species the name of Coryphodon Eocamui. 

 He also describes a tooth found in digging for a well at Camberwell, 

 at a depth of 160 feet in the Plastic Clay. After describing this tooth, 

 Mr. Owen says, " From its close resemblance in the essential characters 

 of its form to the canines of the great extinct Tapiroid Pachyderms, 

 and the apparent specific distinctions from any of the known species 

 of Lophiodon, I strongly suspect it to have belonged to a Coryphodon" 



(Owen, Britiih Poiail Mammalt and Bird>.) 



CORYSTES, a genus of Brachyurous or Short-Tailed Cnutacea. 

 The species have the following characters : Exterior antennae longer 

 than the body, setaceous, with two rows of cilia. Jaw-feet (pieds- 

 machoires) having their third joint longer than the second, straight, 

 terminated by an obtuse point, with a notch upon its internal border. 



Eyes rather distant, borne upon large peduncles, which are nearly 

 cylindrical, and somewhat short. Anterior feet (chelae) large, equal, 

 twice as long as the body, and nearly cylindrical in the males ; in the 

 females, of about the length of the body, and compressed, especially 

 towards the hand (manus). The other feet terminated by an elongated 

 nail or claw, which is straight, pointed, and channeled longitudinally. 

 Carapace oblong-oval, terminated by a rostrum anteriorly truncated 

 and bordered posteriorly. The regions but slightly indicated, with 

 the exception of the cordial region, the branchial or lateral regions 

 being very much elongated. 



Long-Clawed Crab (Corytta Cnssitelaunvs], male. 



C'irystci CassicclauMis, female. 



C. Castivelaunus (Leach), the Long-Clawed Crab ; C. dentata, C. 

 dentatiw, C. longimanut, of Latreille; Cancer Casiivelawiu, Cancer 

 penonatuf, of Herbst; Albtmea dentata of Fabricius. 



This crab has the surface of the carapace somewhat granulous, with 

 two denticles between the eyes, and three sharp points directed 



