of Recent Brachiopoda. 369 



IV. Genus Megerlia, King, 1850. 



In this section a slightly elevated medio-longitudinal crest 

 proceeds from under the muscular fulcrum to less than half the 

 length of the valve, near the extremity of which two short central 

 diverging branches arise and support the calcareous loop, which 

 consists of two riband-shaped lamellae, first attached to the inner 

 side of the socket walls or crural base, afterwards extending to 

 the extremity of the diverging branches to which they are affixed 

 before proceeding on both sides in the same direction to their 

 extremity, under the shape of two nearly parallel longitudinal 

 lamellse, which are afterwards folded back as in Terebratula, 

 forming a loop, but giving off two processes, which affix them- 

 selves also to the extremity of the diverging branches above 

 described ; perhaps in time it will be found necessary to consider 



this genus as a section of Terehratella : two recent species of this 

 genus are known, and it occurs in the fossil state. 



33. Megerlia truncatay Linn. Gmel. sp., 1788; Chem. 1785; 



Sow. Th. Conch, tab. 71. f. 64-67. 



Hab. Coast of Sicily, &c., depth from 60 to 105 fathoms; 

 found fossil at Gibraltar. 



34. Megerlia pulchella, Sow. sp., 1846, Th. Conch, pi. 71. 

 fig. 105-107. 



Hab. Attached to corals at Calapan, Island of Mindoro, &c. 



V. Genus Kraussta, Dav. 1852. 



Shell subcircular, with a nearly straight hinge-line; beak 

 truncated; foramen large, round; deltidial plates small, not 

 united ; beak ridges well defined, leaving a flat false area between 

 them and the hinge margin ; in most species a longitudinal de- 

 pression exists in the smaller valve; the inferior pedicle muscles 

 are large, leaving two wide eye-shaped impressions close to the 

 hinge, and between the inner walls of the socket ridges, a^ small 

 slightly elevated mesial ridge extends to about half the length 

 of the valve, at the extremity of which arise two small forked 

 diverging lamellse expanded at their extremity. 



The ciliated arms are unusually small, their fringes not extend- 



