40 ™.UIKSTRIA,, MOL.USOA INHABITING SOCIKTY IBLANGS. 
, 1 i. f„fo . onfr 6 carinato-rotvindati, seriebus 
carinato costata, subtus siibo so e e cos ‘ . ’j Apcrtura subrlioraboidea, 
™lia„m,„,|,ilon™b..ovium ‘Xr;— et fnlvo fusco les- 
lamella nnioa in anfr. ponultimo munita. Testa satuiati castauco 
scllata. Diam. 5, axis 2 mill.” (Pease). though he was well aware 
I collected Mr. Pease’s type specimens at Huaheinc , o 
of the fact, yet he gave the wrong habitat “Tahiti” to this and several 
species obtained on the former island. ^ • .i _ TTi<! 
The base is never “ carinato-costata.” It is rounded or faintly angulate-. His 
“ pilorura-brevium ” exists in immature examples only. „ , . .1 
Eight vears after receiving from me a lot of Raiatea specimens o t is species le 
published his ceha ” (1. c.). His description is as follows 
“ Testa discoidea, late umbilicata, radiatim tenuitcr, regulariter rugoso striata, 
concentrici irregulariter sulcata aut tenuiter costata ; spira depresso elevata, convexa; 
anfr. 7, rotundato-convexi, pleriimque angulati, ultimus ad peripheriam rotundatus; 
umbilicus yV diametri occupans ; apertura vix.obliqiia subcircularis, lamella unica 
volvcnte instructa ; perist. simplex rectum ; radiatim fusco et albido tessellata. Uiam. 
6, alt. 3 mill.” (Pease). 
The following year he redescribes it under the name of ^'•Endodonta ceha (1. c.), 
without referring to his former diagnosis. I repeat his description : — 
“T. orbicularis, solidiuscula, late umbilicata, tenuissime radiatim creberrime 
striatula, rufo et albido pallide tessellata; spira elevata, apice obtusiusculo, nucleus 
rufesrenti-fuscus, sutura bene impressa ; anfr. 7, convex!, interdum concentrice elevato- 
striati, rarissime sulcati aut angulati, ultimus ad peripheriam obtuse angulatus, subtus 
rotundatus ; apertura obliqua, fere circularis, lamella unica in anfr. peindtimo munita. 
Diam. 7, alt. 3| mill.” (Pease). 
lie gives the correct habitat “Raiatea.” It will be observed that there is some 
discrepancy between the two descriptions of ceha, proving it to be a variable species, 
llis measurement, 6 mill., is correct, but his last one, 7 milh, is larger than any 
specimen known to me. 
Having a second time gone over the same ground and collected hundreds of speci- 
mens, both on Raiatea and Huaheine, I do not hesitate, after a careful study of the 
numerous examples, to add both acetabulum and celsa to the synonymy of obolus. 
I am not positive, but I think I am correct in referring Mousson’s interm>xta (which 
I collected at Raiatea) to Gould’s species. My Barffi, MS , is the Huaheine shell. 
riiis species, in the shape, and the absence of palatal laminae, is nearly intermediate 
between Endodonta and those species of Patula with the single parietal lamina. 
The height of the spire varies from a perfect plane to a depressed cone, hence a 
deeper or shallower umbilicus. They also vary in the distinctness of the periphery- 
keel, and some have that part of the sheU obtusely angular, without the slightest 
