1885.] MOLLUSCA OF THE 'lightning' ETC. EXPEDITIONS. 2/ 



the apparent absence of incremental striae, which are only observable 

 with a lens. On the base this similarity is at once lost through 

 the small, almost microscopical umbilicus and its convex form. 

 The species belongs to the section Conulus of Fitzinger, and may 

 be described as follows : — 



^ 



Hyalina layardi. 



Hyalina (Conulus) layardi, sp. n. 



Testa vLv perfoi-ata, orbiculato-pyramidata, tenuis, superne sub- 

 lente vix striatula, inferne distiiictius striata, oleoso-nitens 

 corneo-lutea, sutura impressa ; an/ractus 5, convexiusculi ; ulti- 

 mus rotundatus, antice non descendens, subtus convexus ; aper- 

 tvra verticalis ; perist. simplex, mcfrginibus callo tenui junctis, 

 iasali convexo, subexcavato coiumellari vix rejiexiusculo. 



Diam. maj. 5, min. 4g, axis 3 mm. 



Hah. Vate Island, New Hebrides. Coll. E. L. Layard and J. H. 

 Thomson. 



6. On the MoUusca procured during the "^ Liglitnino- ^ and 

 'Porcupine' Expeditions, 1868-70. (Part IX.') By 

 the late J. Gwyn Jeffreys, LL.D., F.R.S., F.Z.S.^ 



[Receired January 13, 1885.] 

 (Plates IV., v., VI.) 



GASTROPODA {continued). 



Family XIX. Ianthinid^. 



1. Ianthina exigua, Bruguiere, Encycl. Me'thod. pi. 4.56. f. 2, 

 a, b ; Reeve, Conch. Icon. Ianthina, pi*, v. f. 21, a, b : B C iv' 

 p. 188. 



1 For Part I. see P. Z. S. 1878, p. 393 ; for Part XL see P. Z. S. 1879 p 5.53 • 

 for Part III. see P. Z. S. 1881, p. 693 ; for Part IV. see P. Z S 1881 'p 9-T> • 

 for Part V. see P. Z. S. 1882, p. 656 ; for Part VI. see P. Z S 1883 p 87 • "for 

 Part VII. see P. Z. S. 1884, p. 11 1 ; and for Part VIII. see P. Z. S. 1884 p 341 



^ [Dr. Jeffreys died suddenly on January 24, 188.5, four days after the'readinr^ 

 of bis paper at tlie Society's Meeting. By the request ot' his family I have 

 undertaken to see my much lamented friend's manuscript through the press, 

 but I would wish it to be understood that I do not therefore subscribe to the 

 views and determinations given therein. — EnfiAu A. S.mitii.I 



