350 TEST ACE A ATLANTIC A. 



(Novitat Conch, ii. 297. t. 72. f. 8-12) as the normal state 

 of the H. planorbella, Mousson treats as a ' var. incisogra- 

 nuiata,^ and defines it thus : ' umbilico paulo angustiore, pli- 

 cis minus numerosis, sub lente minute granulatim incisis, 

 margine basali minus adnato, minus incrassato, intus distinc- 

 tius convexo.' 



Judging- from the diagnosis and figm-e, the H. jjlanorhella 

 (wJiich, through a mistake, was cited originally from Porto 

 Eico) is a rounded but depressed shell, with an open umbili- 

 cus, and rather strongly costate-striate on its upper portion, — 

 the costae in the typical (or Gromeran) state being quite simple, 

 but minutely sculptured across (or crenulated) in the 'var. /3. 

 incisogranidata^ from Tenerifife. In colour it is of a pale 

 yellowish-corneous, with two or three more or less evident 

 darker bands; and its peristome has the margins (the basal 

 one of which is widely thickened) a good deal approximated. 



Helix vermiplicata, n. sp. 



T. semiobtecte umbilicata, orbiculato-depressa, subtenuis, 

 densissime et grosse vermiculato-plicata (plicis valde irregula- 

 ribus, submaUeato-confluentibus), et sub lente miuutissime 

 obsoletissimeque arenoso-granulata, subopaca, griseo- vel luteo- 

 albida et fasciis obsoletis 4 vel 5 (sc. 1 vel 2 infra, et 1 vel 

 2 mox supra peripheriam, et 1 pone suturam) suffuse nebu- 

 losa ; spira obtusa, sutura simplici impressa ; anfractibus 5, 

 ultimo magTio inflato sed minute arguteque filo-carinato, antice 

 paulo descendente ; apertm-a lunato-rotundata, peristomatis mar- 

 ginibus ad inseiliones separatis disjunctis. — Diain. onaj. 9j 

 lin. 



Habitat Palmam ; in calcareis ad Argual, regionis occiden- 

 talis ' Banda ' dictse, pauca specimina emortua collegi. 



Out of five examples of this Helix which I met with on 

 the calcareous ' Llanos ' (below Argual) of the Banda, on the 

 western side of Palma, only one is at all mature, and even 

 that one has its peristome stiU unformed ; nevertheless the spe- 

 cies is so well defined by its sculptm-e and other features, that 

 I have ventured to describe it, — feeling satisfied that it can- 

 not be associated with anything else with which we have here 

 to do. 



The specimen to which I have just called attention is so 

 very nearly adult, and has its umbilicus (as in the younger 

 ones) so greatly exposed (scarcely as much as half of it being 

 closed over by the expanded lamina of the lower lip), tliat I 

 feel almost confident that this character of ' semiobtecte per- 

 forata ' will be found to hold good dm-ing all periods of its 



