36 THE VOYAGE OF H.M.S. CHALLENGER 



Parmophorus austrahs, Lamarck, Anim. s. vert, 1st ed. 1822, vol. vi. pt. 2, p. 5, 2d ed., vol. vii. 



p. 579. 

 „ „ Cuvier, Kegne anim. (ed. Desh.), pi. lxv. figs. 1, la. 



,, ,, Chenu, Man. conch., vol. i. p. 373, f. 2801. 



,, „ Eeeve, Conch. Syst., pi. cxxxix. figs. 2, 3. 



„ „ Hogg, Trans. Micr. Soc. Lond., 1868, vol. xvi. pi. xii. fig. 57 (the dentition). 



„ convexus, Quoy and Gaimard, "Astrolabe," vol. iii. p. 322, pi. lxix. figs. 5-16. 



Scutus tumidus, A. Adams, Proc. ZooL Soc. Lond., 1851, p. 222, in part nee Quoy and Gaimard. 

 ,, elongatus, Angas, Proc. Zool. Soc. Lond., 1867, p. 219, No. 212, nee Lam., see above. 

 „ anatinus, E. A. Smith, Journ. Conch., Aug. 1879, vol. ii. p. 257. 

 Parmophorus australis, Tyron., Struct. Conch., vol. ii. p. 329, pi. lxxxiii. fig. 21. 



April 23, 1874. Port Jackson, Sydney. 6-15 fathoms. 



Habitat.— Western Harbour (Q. and G.), Port Jackson, Sydney (Angas and British 

 Museum). 



It will be observed that the synonymy of this species had fallen into extreme confusion, and 

 Mr Edgar Smith, who kindly lent me his list of references (since published, he. cit.), 1 has done 

 admirable service in establishing the true nomenclature of this and the other species of the genus. 



The Port Jackson species, which is very abundant, is Mr Smith's var. a, characterised by an 

 " elongate narrow shell " somewhat contracted in front ; his var. b, with a " proportionally broader 

 shell " (which has a further synonymy of its own), seems confined to Southern and Western Australia. 



3. Zeidora, A. Adams, 1860. 



Zeidora is classed here under the Fissurellida? in accordance with the view of its author, from 

 which, in the absence of the animal, it would be rash to depart. It seems, however, rather an 

 internal than an external shell ; and its true place will probably be found among the Opisthobranchiata, 

 perhaps in the neighbourhood of Pleurobranchus. Crepiemarginula, a genus proposed by Professor 

 Seguenza for a Pliocene fossil of great rarity, is A. Adams's Zeidora. 



Zeidora naufraga, 2 Watson (PI. IV. fig. 3). 



Zeidora naufraga, Watson, Prelim. Keport, pt. 16, Journ. Linn. Soc. Lond., vol. xvii. p. 27. 



Station 24. March 25, 1873. Lat. 18° 38' 30" K, long. 65° 5' 30" W. N. of 

 Culebra Island, West Indies. 390 fathoms. Pteropod ooze. 



Shell. — White, delicate, depressed, oblong, pointed behind, with a minute short apex, 

 rounded and cleft in front, with a broad flat keel bearing the old cleft-scar and extending 

 the whole length of the shell : the enormous mouth is closed behind by a crepidula-like 



1 I have followed his arrangement of authors quoted. 



2 The name was suggested by the resemblance of the shell to a half-decked boat which has been ship 

 wrecked. 



