572 THE VOYAGE OF H.M.S. CHALLENGER. 



The form of the apex, though hardly stiliform, is unlike that of Eissoa, from which genua too 

 the truncation of the base and the want of connection between the outer and inner lips remove this 

 species. I do not know whether Mr Adams would have consented to its admission to the subgenus 

 in which I have put it, but in regard to Stiliferina the difficulty which attaches to several of Mr 

 Adams' groups is increased by the fact that, having removed it from the genus Stilifer, under which 

 and amidst all the relationships of which he originally placed it, he afforded no further indication 

 whatever as to the texture or general sculpture of the shells that might be associated with it in its 

 new relationship as a subdivision of Aldba. That whole group too, loosely defined, has been recon- 

 structed and amended by Mr E. A. Smith (Proc. Zool. Soc. Lond., 1875, p. 537), and in this general 

 removal of the foundations, it is hardly possible to say where Stiliferina now stands. I think, how- 

 ever, it may embrace this species. 



5. Litiopa, Rang, 1829. 



Litiopa melanostoma, Rang. 



Litiopa melanostoma, Rang, Man. Hist. Moll., p. 129. 



„ „ Rang, Ann. ScL Nat., 1829, vol xvi. (1st ser.), p. 303. 



„ striata, Pfeiffer in Wiegmann's Archiv., 1840, vol. i. p. 255. 



,, melanostoma, Eydoux and Souleyet, Yoy. "Bonite," Zool., vol. ii. p. 584, pi. xxxvii. figs. 1-6. 

 Buceinum litiopa, Mrs Gray's Moll., vol. i. pi. xxiv. figs. 1, 2 ; voL ii. pL cvii.a. fig. 3. 

 Litiopa bombyx and Litiopa melastoma (sic), Gray, System. Arrang., p. 70. 



„ bombix, Gray, List of Genera, p. 155. 



„ maculata, d'Orbigny, Cuba Moll, voL ii. p. 149, No. 333. 



„ divisa, Carpenter, Proc. Zool. Soc. Lond., 1855, p. 234, No. 21. 



„ bombyz and Litiopa melastoma (sic), Gray, Guide to Moll., pt. i. p. 96. 



„ melanostoma and Litiopa bombyx, Adams, Genera, vol. i p. 324, pi. xxxiv. fig. 5. 



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

 Island, West Indies. 390 fathoms. Pteropod ooze. 

 June 20, 1873. West of Azores. Surface. 



Habitat. — A species of universal distribution in warm seas, on floating seaweed, and 

 specially abundant in the Sargasso Sea. 



From careful examination of the type shells, I entirely agree with the notes entered on the back 

 of the tablets in the British Museum, bearing Litiopa divisa, Carp., and Litiopa striata, Pfr., that 

 these are this species. Dr Dunker, in his Addenda (p. 64) to his work on Dr Tarn's Collection of 

 Shells from the Guinea Coast, mentions that Litiopa carinata and Litiopa striata, both of Pfeiffer, are 

 the same as the Litiopa nitidula, Pfr., which last, both from his figure and the fact that it is found 

 " in Sargasso natante frequentissima," one could hardly fail to suspect was the same as Litiopa 

 melanostoma. This is also, no doubt, the species referred to by my lamented friend Captain 

 Knocker, R.N. (in the Proc. Zool. Soc. Lond., 1868, p. 617, &c), as Litiopa bombyx (probably 

 Litiopa bombex, Kiener, Ann. Sc. Nat., vol. xxx. p. 121, but he gives no name of author). He 

 mentions having found' it abundant on the Sargasso weed. 



