Ellevte Led er syzygialt og bærer Pinnuler, og fra nu 

 af ere Leddene regelmæssigt afvexlende, saaledes nemlig, at 

 et virkeligt Led afløser et syzygialt* Led, Tab. II, Fig. 1. 

 3 a, b. Pionulerne, hvoraf der paa det omtalte Exemplar 

 var 1 1 paa hver Side. sidde afvexlende og bæres altid af 

 et Dobbeltleds epizygiale Del. og da paa dennes øverste 

 og udvendige Rand, Tab. II, Fig. 3 c, c, fig. 4. Det første 

 Brachiale er 1""" langt og 0.8""" bredt. Dets dorsale Flade 

 er paa Midten saa meget konvex, at det her danner en 

 skarp Kjøl, men skraaner jævnt af til Si&erne henimod de 

 tynde, skarpe Siderande, Tab. II, Fig. 1, 2 k. Den ud- 

 vendige Siderand er ganske fri og skilt fra den tilsvarende 

 paa Sidebrachialet i omtrent 0.5""" Afstand, imedens den 

 indvendige Rand stoder til den indveudige Rand paa det 

 tilsvarende Brachiale. Disse to indvendige Siderande af 

 de første Brachialer slutte sig i Regelen saa tæt sammen, 

 at de faa Udseende af at være sammenvoxede; men en 

 saadan Sammenvoxning tinder kun undtagelsesvis Sted, og 

 da er det alene den nederste Fjerdedel af Randene. der 

 ere sammenvoxede, Tab. II, Fig. 2 1. 



Den ventrale Flade er forsynet med to konvexe Frem- 

 spring, et paa hver Side. Tab. I, Fig. Ila, og som egentlig 

 ere Fortsættelser af Sidefladerne. Disse Fremspring gaa 

 henimod Midten, hvor de bidrage til at danne den dybe 

 Midtfure, Tab. I. Fig. 11b. Sidefladerne ere meget smale 

 og kun lidet konvexe, og der, hvor disse støde sammen 

 med Dorsalfladen, fremkommer den tidligere omtalte, skarpe 

 Rand. Den distale Flade er næsten jævn, har i Midten 

 en liden rund Aabning for Oentralstrængens Gjennemgang, 

 og er forresten ved fast Bindevæv forenet til anden Braehiales 

 proximale Flade. Den underste (proximale) Flade er en 

 sand Artikulationsflade og artikulerer med tilsvarende Led- 

 deflade paa tredie Radiale. Paa Midten af Fladen findes 

 en paatværs gaaende, lidet ophøiet, glat Kam, der deler 

 den i en dorsal og ventral Del. Paa den dorsale Del er 

 en liden, halvrund Fordybning, som tilkjendegiver sig paa 

 den dorsale Flades underste Rand ved et halvmaanefor- 

 migt Indsnit, Tab. II, Fig. 2 m, og som tjener til Insertion 

 for tendinøse Baand. Paa den ventrale Del findes en af- 

 lang Fordybning paa hver Side af Midtfuren, hvilke For- 

 dybninger tjene til Befæstning for to stærke Muskler. 

 Imellem Kammen og den halvrunde Fordybning er den 

 runde Aabning for Centralstrængen. Den proximale Flade 

 begrændses af en rund Rand, der er lidt konvex henimod 

 det halvmaaneformige Indsnit. Denne Rand danner den 

 egentlige Artikulationsflade. 



Derved at den ventrale Flade er meget konvex, faar 

 det første Brachiale en halvrund Form og er langtfra saa 

 sammentrykt fra den ene Flade til den anden, som Tilfældet 

 er med tredie Radiale. 



Det andet Brachiale er lidt kortere og smalere, men 

 forresten ligt det forste, kun med den Forskjel, at begge 

 Siderandene ere fuldkommen fri, Tab. II, Fig. 1. 



Det fjerde og til det ellevte Brachiale er synbart ' 

 smalere, nærmer sig mere Cylinderformen og er paa den 



The eleventh joint is syzygial and carries pinnules, 

 and from this point the joints, become regularly alternating 

 in such a manner that a real joint replaces a syzygial one 

 (Pl. II, figs. 1, 3 a, b). The pinnules, of which, in the 

 specimen spoken of, there were 1 1 on each side. are seated 

 alternatingly, and are always borne by the epizygial portion 

 of a double joint, and then on its uppermost and exterior 

 margin (Pl. II, fig. 3 c, c, fig. 4). The first bracbial is 1""" 

 long and 0.8""" broad. Its dorsal surface is so greatly 

 convex in the middle that it forms here a sharp carina, 

 but slopes evenly off to the sides towards the thin. sharp 

 lateral margins (Pl. II, figs. 1, 2 k). The exterior lateral 

 margin is quite independent, and is separated from the corres- 

 ponding one on the lateral brachial by an interval of about 

 0.5""", while the interior margin unites to the interior mar- 

 gin of the corresponding brachial. These two interior 

 lateral margins of the first brachials close, as a rule, so 

 tightly together that they acqnire the appearance of being 

 concreted, but such a concretion only takes place excep- 

 tionally, and then it is only the lowest fourth part of the 

 margins that are concreted (Pl. II, fig. 2 1). 



The ventral surface is furnished with two convex 

 projections. one on each side (Pl I, fig. Ila), which 

 are really continuations of the lateral surfaces. These 

 projections reach to near the middle, where they contribute 

 to form the deep medial groove (Pl. I. fig. 11 b). The 

 lateral surfaces are very narrow and only slightly convex, 

 and in the situation where they unite with the dorsal sur- 

 face the sharp margin previously spoken of appears. The 

 distal surface is almost even, has a small reund aperture 

 in the middle for the passage of the central cord. and 

 is otherwise united to the proximal surface of the second 

 brachial by finn connective-tissue. The lowest (proximal) 

 surface is a true articular surface, and articulates with a 

 corresponding articular surface on the third radial. In 

 the middle of the surface an oblique. slightly elevated. 

 smooth ridge is found, which divides it into a dorsal and 

 a ventral portion. In the dorsal portion there is a small 

 semi-circular cavity, which evinces itself on the lowest mar- 

 gin of the dorsal surface by a peltiform incision (Pl. II. 

 fig. 2 m), and which serves for the insertion of tendenous 

 bands. In the ventral portion an oblong cavity is found 

 on each side of the medial groove ; these cavities serve for 

 the attachments of two powerful muscles. Between the 

 ridge and the semi-circular cavity is the round aperture for 

 the central cord. The proximal surface is bounded by a 

 round margin, which is slightly convex near the peltiform 

 incision. This margin forms the real articular surface. 



As the ventral surface is very convex the first brachial 

 acquires a semi-circular shape, and is not nearly so com- 

 pressed from the one surface to the other as is the case 

 with the third radial. 



The second brachial is a little shorter and narrower. 

 but otherwise like the first one, with the difference only. 

 that both the margins are perfectly free (Pl. II. fig. 1). 



The fourth. and as far as the eleventh brachial are 

 percepiblv narrower. approaching more to the cylindriform, 



