20 



THE EXTINCT ISATRACIII A, RKITILIA 



(ESTOCEPHALTTS PECTINATTJ8, Cope. 



Bawropleura pectinata, < !<>ix;, loo. cit., 1868, 21H. 

 This species is represented by portions (if the vertebra] columns of four individuals. Tn two of these, vertebra] 

 centra are discoverable, in one quite definitely. They are slightly constricted medially, and without ridge or 



process. 



The neural and haemal spines of superior and inferior lines are similar, and in the specimens undistinguishable. 

 The dilated portions form nearly equilateral triangles, which stand on moderately short pedicels. They are weakly 

 ridged, and each ridge is prolonged into a narrow acute tooth, beyond the margin of which eleven maybe counted 

 on oih! of the best preserved. The longitudinal striae are terminated near the pedicel by two others which cross 

 obliquely from each side and meeting present an appearance similar to an overlapping of each margin. The 

 edges of the spines form a continuous line. 



As in the other species, there are no indications of other processes, nor of dermal scales. 



The smallest of the specimens shows that in front of the region furnished with the peculiar spines described, the 

 body is furnished with a mass of bristle or hair-like scales. The grooved neural spines are slightly displaced 

 anteriorly, and the bristle-like mass looks like a continuation of their striae, and it is not easy to find any line of 

 demarkation between them. The serrate spines are further forwards on one side than the other. These 

 linear scales were arranged as in other genera,, in lines which converge forwards to the median line. They are 

 somewhat obscured in the specimen, but it cannot be determined that they are continuous on the median line. 

 Whether this is the posterior or anterior portion of the body cannot positively be determined from the specimen; it 

 is, however, most likely the posterior, for near the posterior portion of the striate surface a weak pair of 

 limbs is given oft' on each side. On the right, a moderately stout femur is followed by a broken tibia 

 and fibula, and by five slender, closely oppressed metatarsals. The last are about 2-5 as long as the space 

 between them and the femur: beyond them a few slender phalanges are moderately distinctly defined. The 

 tibia is more distinct on the left, but no tarsus or phalanges; some of the metatarsals are preserved here 

 also. Length of limb to end of metatarsals equal to five vertebra in juxtaposition, measured along the edges 

 of the neural spines. The limb has been slender, especially the hand. 



The above specimen enables me to assign as the ventral armature of this species a closely packed series of 

 V-shaped grooves which lie in connection with an obscure vertebral column, on the block containing one of the typical 

 specimens of this species. They are not continuous with any of the series exhibited on other pints of the block : 

 some of these at least are the doublings of the slender animal, and this ventral portion has been displaced. The 

 grooves are like the impressions of haemapophysial rods, vastly more numerous however than the number of 

 vertebra ; they a,re really the dermal armature. Huxley figures a portion of this as on the block with the 

 Orooordylus wandesfordii, but does not refer it to a precise relation to the animal. A few well developed ribs are 

 preserved with this portion, the only ones I can refer to this species. The vertebrae are partly enclosed in matrix, 

 partly impressions. The neural spines, though expanded anteroposteriorly, are less elevated than in the caudal region, 

 and have left no traces of their characteristic ribs or serration. 



The number of spines in the type specimens is six in a, half inch ; in tin; smallest, just described, ten in the same 

 distance. The height of the spine in the former 1.15 lines. 



MOLGOPHIS, Cope. 



Loc. Cit 18(18, 22ti. 



This genus is established on remains represented by three specimens, which arc two 

 scrips of dorsal vertebras with ribs, and a series of caudals. One of the dorsal scries 

 embraces sixteen vertebras, the other fourteen, (lie caudal series, twenty-two. 



From its serpentine form this germs may be compared with the Dolichosoma of 

 Hnxley, though' a close relation does not exist between them. In the Irish genus; the 



