165 

 Magasella Tenisoni, Woods. Plate xi., fig. 5a— 5c. 



Reference. — Terebratella Tenisoni, Trans. Phil.JSoc, Adel- 

 aide, 1865, t. ii., figs. 5a, 5b, and 6. 



"Shell elongated, usually convex. Peduncular valve, trapezi- 

 form, keeled deeply, and terminating in a notch at the anterior 

 margin. Brachial valve orbicular and tapering to a point 

 which fits into the notch on the other valve. Beak obtuse, 

 deltidium striated, foramen oblong. 



" Septum thickened, curved, and produced so as to touch the 

 opposite valve ; attachments of the loops at the centre, and 

 nearer to the shell than to the edge of the septum. Muscular 

 impressions deep. Hinge and crura sloping away from the 

 septum, with a deep sinus in the centre. 



" Size, variable, but adult specimens 0"7, breadth 0'4 of an 

 inch. 



"This curious species has strong points of resemblance to- 

 T. JEvansii, but whose individual characters are very distinct. 

 In both the septum is produced so as to touch the opposite 

 valve." — Woods. 



Locality. — Mount Grambier and Portland (Woods). 



Magasella deformis, spec. nov. Plate x., figs. 5a— 5c. 



Shell oblong-ovate, margins of sides convex in the middle. 

 Peduncular valve very convex, obtusely carinated along the 

 middle, sides convex becoming flat or slightly concave near the 

 lateral margins. Brachial valve regularly convex in the 

 umbonal half, with lateral margins abruptly reflected, becoming 

 abruptly and considerably depressed towards the narrowed 

 front. 



Beak depressed, truncated by a minute foramen ; deltidial 

 area broad and concave ; beak ridges well defined. 



Surface with a few lines of growth ; malleated punctate 

 under a lens. 



Mesial septum thick, about half the length of the valve, 

 abruptly produced so as to touch the opposite valve ; diverging; 

 lamellae of loop nearly parallel, connected by short transverse 

 processes to the point of origin of the septal projection ;. 

 thence continued beyond for about half as far again, 

 widening at the inflection, and apparently becoming attached. 

 near the apex of the septal projection. 



Dimensions. — Length, '45 ; breadth, - 3 ; depth, "27 of an inch. 



Observations. — The reflection of the lateral margins of the 

 valves is a character belonging to the adult shell. In its- 

 young state it resembles M. compta, and somewhat M. Woodsiana 

 at the same stage of growth, but is at once distinguished by ite- 

 beak and its malleated test. 



