HISPANIOLAN AND BAHAMAN ANNULARHDAE 119 



Linnaean Lister,^^ who illustrates somewhat poorly what we have called 

 Licina labeo (Miiller). 



Miiller in his description gives the shell a length of 15 lines, i.e., a 

 little less than 32.0 mm.; the figure has a length of 33 mm.; but the 

 peculiar way in which it is placed and drawn gives it the aspect of a 

 much larger moUusk. No mention is made of the country from which 

 it was derived. Subsequent authors have assigned the name to the huge 

 form that we are now able to proclaim a denizen of the north coast 

 of the southern peninsula of Haiti. 



When Henderson and I published our "Classification of the American 

 Operculate Land Mollusks of the Family Annulariidae,^*^ we stated on 

 page 53 that the operculum at that time was unknown and that we were 

 for that reason unable to assign a definite position to Gray's genus 

 Licina in the system we were proposing. 



Our collecting in Haiti has removed this difficulty, and I am now 

 able to state that the operculum consists of a thin basal chondroid plate 

 upon the outside of which is placed a covering of calcareous deposit 

 from which rise retractively curved lamellae ; these expand on their free 

 edge where they fuse to form a thin plate. The outside of this plate, 

 which parallels the basal chondroid plate, shows the riblets. The riblets 

 and the plate formed by their fusing do not extend over the entire 

 width of the opercular turns but leave a decidedly plain space at the 

 outer margin, which separates the calcareous deposits of the succeeding 

 whorls. The outer edge of the pseudolamellar outer plate turns upward 

 and leaves a peripheral groove. This, in a number of species, gives the 

 operculum a sort of 3-stage effect, which is especially emphasized in 

 those species in which the riblets are not entirely fused on their outer 

 edge. The fused outer plate is easily broken away and not infrequently 

 only the indications of the remnants of the radiating riblets remain. 

 Students are cautioned, therefore, to be very careful in studying the 

 opercular characters of this group, which appears confined to Hispaniola 

 and whose largest species it embraces. 



Type species : Nerita labeo Muller = Licina labeo (Miiller) . 



In spite of the above disposition of the name Licina, its status is by 

 no means certain, for in the "Amtlicher Bericht uber die 24. Versamm- 

 lung Deutscher Naturforscher und Aerzte in Kiel im September 1846," 

 pubHshed in 1847, H. Beck uses Licina Browne as a subgenus of 

 Cyclostoma citing only L. elegans Draparnaud. Gray's use of the 

 name Licina dates from November 1847. I^ the Bericht referred to above 

 was published earlier in 1847, then L. elegans Draparnaud {=Pomatias 

 elegans (Muller)) becomes the type of Licina Beck and a synonym of 

 Pomatias, and the Hispaniolid shells listed under Licina Gray must have 

 another designation — as such I now propose Graypoma. 



" Historiae sive synopsis methodicae conchyliorum, pt 1, pi. 25, fig. 23, 1685. 

 i« Proc. U. S. Nat. Mus., voL 58, pp. 49-82, 1920. 



