Eglis^ia, Callostracum, Mesalia, ^-c. 371 



1891. Aeirsa sitbdtvussata : Locard, Coq. Marin. France, p. 128, fig. 112. 

 1897. Scalaria {Aeirsa) suhdecussata : Watson, Journ. Linn. Soc. 

 vol. xxvi. p. 315. 



Hah. Atlantic coasts of France and Spain, Mediterranean, 

 Madeira, and Canaries. 



I have compared the types o£ Turritella inci'sa, Eeeve, 

 recorded as from Sydney, Australia, and Mesa/m striata, 

 A. Adams, stated to be from the Philippine Islands, with 

 Mediterranean and Madeiran specimens, and 1 am convinced 

 of their identity. I therefore regard the localities given by 

 Reeve and Adams merely as further examples of errors of 

 this kind which occur in the Cuming collection, from which 

 the species were described. It is included in Mr. Whitelegge's 

 list of the fauna of Port Jackson * merely on Reeve's 

 authority. 



According to Monterosato, the animal of this species 

 resembles Scalaria in the position of the eyes and the form 

 of the tentacles, also in tiie median longitudinal oroove of 

 the foot. The head has no cylindrical and retractile proboscis. 

 He described the operculum as horny, with a spiral nucleus, 

 placed towards the inner side of the mouth, and composed 

 of a small number of whorls and marked with strong lines of 

 growth. Fischer also described the operculum as pauci- 

 spiral, with a lateral nucleus like that of Scalaria and Lilto- 

 rina. It will thus be seen that it agrees with that of the 

 type of Mesalia {M. hrevialis), which is incorrectly figured 

 as multispiral with central nucleus by H. & A. Adams (Gen. 

 Rec. Moll. vol. iii. pi. xxxviii. figs. 4o, Z»), resembling that 

 of Turritella. 



There are in the British Museum two specimens of 

 M. hrevialis, from Goree, with opercula which agree closely 

 with that ot Epitoniuvi {Scalaria) or Littorina. The shell- 

 characters of the present species {suhdecussata) differ from 

 those of AI. hrevialis in some respects. The upper whorls 

 are longitudinally costate, the outer margin of tiie peristome 

 is not sinuated above, and the basal sinus is only faintly 

 developed. It agrees with M. melanioides in being lonoi- 

 tudinally costate and the non-sinuation of the labrum, but it 

 lias not the marked basal sinus as developed in that species. 

 Since, however, so little is known at present with regard to 

 the animals, I think it preferable to leave this species in 

 Mesalia rather than Aeirsa, or to create a new genus for its 

 reception. 



• Journ. Proc. Roy. See. N.S.W. vol, xxiii. p. 2G2 (1889), 



