1849.] SHARPE ON THE SECONDARY ROCKS OF PORTUGAL. 191 



covered by irregular concentric lines of growth, which are best seen 

 between the tubercles. 



Length 2 inches ; breadth 3 inches ; thickness 1^ inch. 



Abundant in limestone of the subcretaceous period between Torres 

 Vedras and Sobral. 



Goldfuss has figured a specimen of this shell from Torres Yedras, 

 uniting it to T. liter at a of the lias and inferior oolite, from which it 

 is quite distinct. The Portuguese species is a neater and more re- 

 gular shell, and may be distinguished from T. liter ata by its straight 

 front and by the regular rows of small tubercles which cover nearly 

 half its surface, while the same part is covered in T. literata by 

 broad coarse ribs. The principal character which is common to the 

 two species is the bifurcation of the rows of tubercles towards the 

 front of the shell ; this is not common among the Trigonise, but is 

 seen also in T. muricata, T. dcedalea, T. nodosa and T. duplicata. 



The Trigonia muricata, Goldf. sp., which is found in the same lo- 

 cality, is so closely allied to T. Lusitanica, that it may be doubted 

 whether they should not be united : the general form of the two shells 

 is the same, but T. ynuricata has about twice the number of rows of 

 tubercles, which are smaller and more numerous in each row than in 

 T. Lusitanica. 



Plate XXII. fig. A a & b. Two views of the same specimen. 



Spirifer Beirensis, n. s. Pl. XXVI. fig. 2 a &l 2 b. 



Shell ovate, moderately convex, minutely punctated : dorsal valve 

 regularly arched, with a produced incurved beak, and a broad shallow 

 ill-defined sinus extending from the beak to the margin, where it oc- 

 cupies above a third of the width of the shell; ventral valve nearly 

 circular, with a broad, rounded, ill-defined mesial fold : both valves 

 are smooth near the hinge, and are ornamented towards the front 

 margin with faint, rounded, longitudinal folds, separated by shallow 

 rounded furrows ; of these there are about eight on each wing, of 

 which the lateral ones are very obscure ; faint traces of obscure folds 

 in the sinus : a few strong concentric rings on each valve. Hinge- 

 area rounded off and undefined. 



Length 1 inch ; breadth f of an inch ; thickness \ inch. 



In Jurassic limestone at Vendas Novas, four leagues north-west of 

 Coimbra on the road to Aveiro. 



This shell belongs to the same group of punctated Spirifers as S. 

 Walcottii, S. granulosus, and S. verrucosus, all of which are found 

 in the lias. It was found in company with ^S". granulosus and other 

 shells peculiar to the lias. It is distinguished from all its congeners 

 by its elongated ovate form and obscure ribbing, in which it closely 

 resembles many of the recent Terebratulce, especially T. dentata. 

 In fact, of all the Spirifers known, this is perhaps the species most 

 nearly allied to the Terebratulse. 



The ribbing is much more marked on the dorsal than the ventral 

 valve ; but as the only specimen seen appears somewhat worn, this 

 may be partly accidental. 



