T5L: IRA (T.:OSSELIA) HSDSRSOri Dall. 



TelliriL ' Mo«rellaJ_ hendersoni Ball, 1900, Trans, ''/agner ?ree Inst. 

 Sei., Philadelphia, vol. ?, pt . 5, pp. 1024-1025, pi. 

 46, fig. 5. 



DesQription .- "Shell small, raoclerately conve- , verj/ ineq-.ii- 

 lateral; from resenibling the oreceeding species _T. sinrosoni but 

 less inflated, riiore rG~-iilar, r.'ith posterior en. not constricted 

 or markedly? flexed; surTaee polished, v/ith, except near the beaJcs, 

 f ne, rather distant, concentric threads, which on the basal half 

 01 the posterior end rise into er-'tremely delicate lo\v lamellae; 

 hinge norraal, strong; pallial sintis connecting the adductor scars 

 and confluent belov;; there is a slirrhtly i-npressed narrov/ lunule. 

 l-Q-n.. 7.5, alu. 4, lam. '^ -^m." 



"This soecies differs in soulptnTe, form of lihe pallial sinus, 

 and other details from the other allied forms." (Dall, 1900). 



"S-^-ge local it-- .- Borden, Jamaica. 



!^emarks .- _T. hendersoni shares v/ith j£. acrocQsraia the 

 distinction of be in?? the most abundant member of the genus. It 

 oloselj* resembles _^. oimpsoni . the most obvi vas differen-e bei::'^- 

 the absence of a posterior constriction on the present form. Sep- 

 arated on this basis, hendersoni is larger than sinpsoni , one of 

 the largest valves of the former ayiecies . ,uat..-.ri.i;; o mm. in length. 



