NATURAL SCIENCES OF PHILADELPHIA. 478 



Taret du Senegal. Adanson, Hist. Nat. du Senegal, p. 264. t. 19. Adanson, 

 Mem. de l'Acad. des Sc. 1759, p. 278, t. 9, f. 9, 10. 



Hab. In Mangrove roots. Coast of Senegal. 



Description. "Coquille un peu plus grosse, plus evidemment rhomboidale, 

 ou a quatre cotes obliques. Le bord tranchant strie de vingt-cing stries denti- 

 culees. Pallets en spatule tronquee et non bicornee. Cette espece, qui est in- 

 dubitablement distincte du taret commun, quoiqu 'il soit assez difficile de la 

 caracterisee completeinent, ii cause du peu de details dans lesquels Adanson 

 est entre a son sujet, est fort commune dans les racines des mangliers qui 

 bordent les fieuves Niger et de Gambie. Elle les perce verticalement, quel- 

 quefois a deux ou trois pieds ; mais ordinairement a six pouces au dessus de 

 terre. ' ' Blainville. 



T. t r u n c a t a, Quatrefages. 



T. truncata, Quatrefages, Ann. des Sc. Nat., 3d ser., xi. p. 27. Adams, 

 Genera, ii. p. 333. Fischer, Journ. Conch., 2d ser., i. p. 133. Jeffreys, 

 Ann. and Mag. Nat. Hist., 3d ser., vi. p. 126. 



Hab. Aniboina, Quoy et Gaimard. 



Description. " Coquille fragile, presque spherique, fortement echancxee et 

 anguleuse & son bord anterieur ; Tangle anterieur est de 90 environ, son 

 sommet se trouve place assez en arriere, et ses bords paraissent plus rectilignes 

 que dans la plupart des autres espcices. Stries de l'oreillette anterieure assez 

 irregulieres, si ce n'est vers les bords ; palettes pediculees, tricuspides, ob- 

 liquement taillt-es en biseau de dehors en dedans." Fischer. 



Quatrefages' Description is " testa fragili, quasi sphserica, alte 



eniarginata ; emarginatione 90 gradibus hiante ; palmulis pedicellatis, in ob- 

 liquum truncatus, tridenticulatis." 



Subgenus Calobates, Gould. 



Calobates, Gould, Proc. Bost. Soc. Nat. Hist., viii. p. 280, Feb., 1862. Gould, 

 Otia Conchologica, p. 241, 1862. 

 Description. "Pallets stilt-shaped, bony. Type T. thoracites, Gould." 

 I owe to the kindness of the author, an opportunity to examine specimens 

 of the valves of this interesting shell, and also a sketch of the pallets. The 

 latter are indeed very remarkable, and indicate very clearly a subgeneric, if 

 not generic distinction, from Teredo. A more particular description of them 

 is contained in that of the species. 



T. thoracites, Gould. 



T. thoracites, Gould, Bost. Proc, vi. p. 15. Gould, Otia Conchologica. 

 p. 222, 241. 



Hab. Burmah. 



Description. " Shell large, solid, length and breadth about equal; valves 

 trifoliolate, the anterior area or leaf being very large proportionally, or about 

 equal to the fang-like body, excepting that it is truncated anteriorly, where it is 

 smooth, shining and callous. This anterior area is obtusely lance-pointed and 

 sculptured with concentric strise parallel to its basal edge, and with a few 

 delicate cracks or rugae radiating from the beaks ; the fang-like body is large 

 and broad, obtuse at point, and armed within by a firm rib, terminating in a 

 rounded ivory knob ; a strong flattened ridge traverses its posterior extremity, 

 running from the junction of the posterior wing above to the point of the fang ; 

 anterior to this the fang is grooved parallel to the anterior edge; while pos- 

 terior to it they take the direction of the inferior edge of the wing, and be- 

 come gradually more and more recurved towards the point, and are continued 

 on to the ridge. The posterior dorsal wing is very small and lunate, not 

 rising above the beaks, gently arched, scarcely projecting beyond the poste- 

 rior margin of the fang, its lower margin would correspond with the lower 



1862.] 



