OP CONCHOLOGY. 



151 



Fig. 27. 

 Fig. 27. T/iecidium mediterraneiim, haemal valve with the animal, four times 

 the natural size. From a specimea in the collection of Thos. Davidson, Esq. 



Thecidium Mediterraneum^ Sby., Thes. Conch, vii, p. 371, pi. 

 73, fig. 30-32. Lacaze-Duth., loc. cit., p. 262, pi. i — iv. 



This species is found attached to corals in the Mediterranean. 

 It is the T. testudinaria, Michel., and the T. spondylea, Scacchi. 

 It has also been found in Jamaica. 



Thecidium Barretti, Woodw., Geol. Mag. 1864, i, pi. ii, fig. 1 

 —3. Dav., P. Z. S. 1866, p. 104. 



This species, first described from fossils, has been found living 

 on the coast of Jamaica, at 60 fathoms. 



Family RHYNCHONELLIBM. 

 Genus RHYNCHONELLA, Fischer. 



Fig. 28. Fig. 29, 



Fig. 28. Neural aspect of lihynchonella acuminata, fossil, from a cast, show- 

 ing vascular impressions. 



Fig. 29. Umbonal aspect of the same, a, adductor scar ; R, cardinal ; p. 

 pedicel ; v, vascular ; o, ovarian impressions. 



ll/tynchoneUa, Fischer, Not. des Fos. du Gouv. de Mosc. 1809. 



