266 TEST ACE A ATLANTIC A. 



vex, Helix-shaped form, its solid consistency, its opake, pallid, 

 concolorous, yellowish-fulvescent surface (which is coarsely 

 sculptured with regular, but not very closely set, transverse, or 

 ' spiral,' striae), and by the peculiar construction of its large, 

 wide, open, somewhat semicircular aperture, which is furnished 

 with an enormously developed, curved, elongate ventral plait, 

 or process, at a short distance from the angle of the lip, and 

 two smaller ones on the extremely broad, flattened, white, cor- 

 neous columella (the upper one, however, being larger than the 

 lower). Its outer lip is acute, but the lower half of it (or, more 

 properly, perhaps, the central region) has a gradually-thickened 

 callosity inside, which developes into a blunt medial tooth, and 

 a much less elevated, obscurer one immediately above, the 

 two being intimately connected by the incrassated inner space. 



Genus 16. MELAMPTTS, Montf. 



Melampus exiguus. 



Melampus exiguus, Lowe, Zool. Journ, v. 291 (1835) 

 Auricula exigua, Id., Proc. Zool. Soc. Land. 218 (1854) 

 Melampus exiguus, Pfeiff., Mai. Bldtt. xiii. 133 (1866) 

 Paiva, Mon. Moll. Mad. 150 (1867) 



Habitat Maderam ; sub lapidibus juxta mare, prsecipue ad 

 litus boreale Promontorii ( Ponta de Sao Lourenpo ' dicti, necnon 

 prope Seissal, rarior, una cum Auricula cequali, Pedipede 

 afra, et Truncatella truncatuld degens. 



The greatly abbreviated and broad (but apioally acute) spire 

 and elongate aperture of this little Melampus, which give the 

 shell (which is extremely variable in size) a rather turbinate or 

 coniform outline, added to its solid consistency, it pale yellowish- 

 brown hue (accompanied often by a rosy, or even lilac, tinge, 

 which is particularly appreciable in the examples from the 

 Salvages), the fine, sub-undulating transverse (or ' spiral ') striae 

 with which it is sculptured, its completely edentate outer-lip 

 (which however is furnished internally with a thickened longi- 

 tudinal callus, parallel to the margin, but vanishing before it 

 reaches the angle), its plicate columella, and its bi-plicate ven- 

 tral region (the upper of the two callosities being often minute, 

 and occasionally even obsolete) will suffice to distinguish it 

 from its few allied forms with which we have here to do. 



The M. exiguus appears to be somewhat rare, and was first 

 detected by Mr. Lowe on the northern shore of the Ponta de 

 Sao Lourenpo in the east of Madeira proper, where it resides 

 beneath stones, in company with the Auricula cequalis, Pedipes 

 afra, and the Truncatella truncatula, below the high-water 



