20 CATALOGUE OF PTEROPODA. 



7. THECA. 



Shell fossil. 



Theca, Forbes, Quart. Jour. Geol. Soc. ii. 314, t. 13, 1846 ; Leonard 

 ^ Bronn, Jahrb. 1847, 634. 



1. Theca Forbesii. 



Sheath nearly flat behind, rounded in front, conical, and tapering 

 to a point ; aperture an obtuse-angled triangle, with the angles 

 rounded off; surface finely striated, arched parallel to the edge of 

 the mouth. 

 Theca Forbesii, Sharp, Quart. Jour. Geol. Soc. ii. 314, t. 13, f. I. 

 Fossil. Ludlow Rock, middle part Kendal. 

 a. Fossil. Presented by S. Woodward, Esq. 



2. Theca lanceolata. 

 Theca lanceolata, Morris. 



Fossil. Palaeozoic Rocks, New South Wales. 



8. CONULARIA. 



Shell quadrangular, with a longitudinal groove at each angle ; sides 

 regularly transversely striated. Fossil. 



Conularia, Muller, in Soiv. Mon. Conch, iii. t. 108, 1818, 1821, t. 

 260; Brown, Leth. 97, 1837; Blainv. D. S. N. xxxii. 193, 1824 ; 

 Malac. 377, 622; Flem. B. A. 240, 1828 ; Sow. Man. ed. 2, 119 ; 

 D'Archiac I- De Verneuil, Trans. Geol. Soc. vi. 325, 1842 ; D'Orb. 

 Bull. Geol. France, xiv. 563 ; Austin, Ann. and Mag. N. H. xv. 

 407, 1845 ; Leon. ^ Bronn, Jahrb. 1843, 639. 



Sowerby, when he first described this genus, regarded it as allied 

 to Nautilus. Fleming keeps it in the same situation. Blainville 

 placed it with the Orthocera. Hoeninghaus showed, in 1839, that 

 it had no chambers, and Messrs. D'Archiac and De Verneuil referred it 

 to Pteropoda. D'Orbigny formerly {Voy. Amer. Merid. Moll. 119, 

 note) thought it was a Pteropod, but more lately he has regarded it 

 as a Heteropod. I have sometimes thought it might be related to 

 Asterias : it is placed here with great doubt. 



