OF CONCHOLOGY. 



101 



Family TEREBRATULID^. 



Shell punctate. Neural valve perforated at or near the apex, 

 and attached to submarine objects by a peduncle passing through 

 the perforation, or by a portion of the valve itself; provided 

 with two teeth, which are articulated into sockets in the haemal 

 valve, which, in its turn, possesses a more or less prominent 

 (cardinal) process which interlocks with the neural valve. 



Animal with ciliated brachia more or less provided with non- 

 spiral calcareous supports, which proceed from the haemal valve. 



Section TEREBRATULIN^. 



Haemal valve Avith a simple loop proceeding from the hinge 

 margin, more or less sinuate, and possessing two pointed pro- 

 cesses or crura which have their origin near the hinge margin, 

 to which alone the loop is attached. Deltidium composed of two 

 pieces, often united. 



Genus TEREBRATULA (Llhwyd), Auct. 



Shell provided with a simple sinuous loop. Crura separated. 

 Neural valve perforate at or near its extremity; attached by a 

 pedicel. 



Fig. 1. Fi 



Fig. 1. Terebratula vitrea, Born, hsemal valve. 

 Fif. 2. Same, with the animal. 



Subgenus Terebratula (Llhwyd), Auct. 



Shell ovate, margin entire. Brachia passing behind the 

 mouth, provided with two symmetrical lateral lobes and a double 

 spiral median lobe. 



Tupe. Terebratula niaxillata, Sby., Min. Conch, p. 52, pi. 



436, f. 4, 1822, = 

 T. minor subrubra, Llhwyd, Lith. Brit. Ichn. 1699, pi. xi, fig. 



890. 



8 



