RKMAINS TX THF. COAL-FOllMATIOX 01' NOVA SCOTIA. C41 



minute teeth. The mandibles found are not comi)lete, but there are indications that 

 there was an ascenchno- process as in //. Dawsoiii, but less developed. Tiie narrow- 

 ness of the dentary bone in Plate 42, fio-. SC, is caused in part by the lower posterior 

 edge being bent inward at {'(), and by the posterior end being broken oft' above. 



Vertebra) short and stout, and apparently well ossifiet^ llibs long, with double head 

 and much curved. 



Humerus longer than the femur, which is short and stout, if the bone taken for it is 

 rightly determined. 



Abdominal scales narrow, oat-shaped ; thoracic , late largo, broadly oval. 



Length of mandible 4 centnnetres. 



,, vertebra 5 millimetres. 



,, rib ..... .... 2'') centimetres. 



,, luuneriis I'.") ,, 



femur (0 \-2 



,, tibia 8 millimetres. 



,, mandibular teetii .'5 ., 



Six to seven teeth in 1 centimetre. 



Under the microscope, the bone shows somewhat elongated cells similar to those of 

 //. Datcsoni, but smaller. Tlio tcctli in cross-section near the base, present a some- 

 what complex structure, though the dentine is not folded. Next the pidp cavity 

 there are straio-ht radiatino: cells or tubes, coarse and with lateral canaliculi. This 

 structure, which resembles tliat of JI. Dairnimi, extends about half way to the .surface, 

 when the Inrse tubes C(vise and the can.'diculi form a dense network. On the outside of 

 this is a thick layer of enamel with line straight canaliculi. A section nearer the 

 apex of the tt)oth would probably show a less thickness of the second (jr intermediate 

 layer. 



8. Fi-itsvhia ritrdili'iifatn, s.n. (Plate 43, figs. 110 to l'_'y\, 



[ITjh'fpdvn t-nrtidcnfatinn, I'relimiuary Notice, American Journal of Science, I.e.] 



This species is re]iresented in the collections by two specimens— one well preserved 

 and probably adidt, the other smaller and less perfect. In 187f), when I ])ossessed 

 but one specimen, I referred \t to Ili/lrrpcfon ; but it diifers from that geinis in the 

 absence of ]>alatal teeth and in the abdominal armour, which consists t)f long slender 

 rods instead of scales. This kind of protective structure, as is well known, occurs in 

 IIuxLKv's genus < >/)hiiIrrpcfi>a—ii creature otherwise vciy dillci-ent — and in ('(U'h'.'s 

 Saiiropli'iini, which in the ])arts known has much resemblance to the present genus.-' 



* Ci'i'tiiin spccii'M (if I'nronhihi.'i doscrihiMl liy llrxMV iiiiil I'laisoii woiilil sccni to I'Vcsciit forms of 

 sciilcs iiiti'i'iiu'iliiilu Ijriwccii llif o!it-sliii|ic(l mid Vdd-likc Ivpcs. 



I N -1 



