462 PROCEEDINGS OF THE ACADEMY OF 



body glossy, marked with distant, but regular and fine, stria? or impressed lines ; 

 anterior auricle placed nearly at a right angle with the insertion of the fang, 

 striae rather numerous and waved ; posterior auricle dilated and somewhat re- 

 flected, apex nearly on a level with the crown or umbo of the valve, inner mar- 

 gin free and well defined; tubercle slight, and not visible when the valve is in 

 a supine position; fang obtuse; apophysis thin and narrow. Pallets long and 

 narrow, bifid in front to nearly half their length, with two corresponding tubu- 

 lar cavities which terminate in separate points like the prongs of a steel fork ; 

 underneath they are abruptly sloped towards the bifurcate points, and closely 

 striated in a longitudinal direction ; stalks near as long as pallets, pointed at 

 one end and at the other merging into the pallets. 



Dimensions. Length (of valves) 7-20tbs ; breadth 4-20ths." Jeffreys. 



T. f u s t i c u 1 u s, Jeffreys. 



.T. f u s t i c u 1 u s , Jeffreys, Ann. and Mag. Nat. Hist. 3d ser. vi. p. 125. 



Hab. In Cedrella odorata from Leith. 



Description. " Tube short and straight, with a slight calcareous lining, which 

 is not easily separated from the wood. It is thickened internally at the opening, 

 and has a few transverse wrinkles in that part. 



Valves round, thin, compressed, body smooth, glossy, white under a brown 

 epidermis ; anterior auricle of moderate size, angle about 50, striae numerous ; 

 posterior auricle round expanded and appressed to body, internal edge well de- 

 fined ; fang broad, obtuse ; tubercle small and sunk ; apophysis thin and narrow. 

 Pallets club-shaped, formed of several transverse layers, and externally tuber- 

 culate ; stalk twice the length of pallet. 



Dimensions. Length, (of valve) 4-20ths ; breadth nearly as much." Jef- 

 freys. 



T. spa th a, Jeffreys. 



T. spatha, Jeffreys. Ann. and. Mag. Nat. Hist. 3d ser. vi. p. 124. 



Hab. With T. bipartita, in Cedrela odorata, at Guernsey. 



Description. " Tube rather long and flexuous, detachable, regularly jointed, 

 increasing rapidly from the extremity, inside which there are a few transverse 

 wrinkles and a sharp, but short, siphonal ridge. 



Valves, triangular, compressed, rather solid ; body smooth ; anterior auricle 

 large, angle about 50, striae exceedingly numerous and fine ; middle area un- 

 usually large and rounded and appressed, internal margin indistinct; fang nar- 

 row and pointed ; tubercle small and sunk ; apophysis narrow. Pallets spade- 

 shaped, in the young state calyciform ; stalk of the same length as pallet. 



Dimensions. Length (of valves) 6-20tbs; breadth nearly as much. A pair 

 of pallets is in the British Museum, from Miss Saull ; and another pair is in the 

 collections of Natural History at the Jardin des Plants. The localities of both 

 the last-mentioned specimens are unknown." Jeffreys. 



T. subericola, Macgillivray. 



T. subericola, Macgillivray, Mss. Jeffreys, Ann. and Mag. Nat. Hist. 3d ser. 

 vi. p. 122. 



Hab. Great Britain. 



Description. Tube rather thin, and adherent to wood, short, of the form of 

 an elongated cone curved at the opening, with internal irregular transverse sep- 

 ta, which are close-set at the extremity. 



Valves oval, rather convex, thin ; body smooth and somewhat glossy ; ante- 

 rior auricle short, angle obtuse, striae rather numerous; posterior auricle nar- 

 row, falciform, reflected at the outer edge, with its apex raised above the crown ; 

 tubercle strong and prominent; fang long, narrow, and incurved ; apophysis 

 rather broad. Pallets short, pear-shaped, compressed, and expanded towards 

 the anterior margin, with a semilunar depression in the middle and a longitu- 

 dinal groove in front ; stalk short and pointed. 



[Sept. 



