ZOOLOGY OP FERNANDO NORONHA. 
491 
22. Littorina trochiformis, var. ? (Plate XXX. fig. 2 .) 
Littorina trochiformis, Dillwyn, Philippi, Ahbild. vol. ii. p. 143, pi. ii. 
ff. 12, 14, 15. 
Littorina nodulosa, Watson ( non Gmelin), ‘ Challenger ’ Gasteropoda, 
p. 577- 
Testa parva, fusiformi-ovata, grisea vei nigrescens, albo-nodosa ; 
aufractus 6-7, convexiusculi, superiores granorum seriebus tribus 
ornati, striisque spiralibus elevatis paucis sculpti, ultimus in 
medio obtuse angulatus, seriebus quatuor ciuctus, ad basim albo 
punctatus ; apertura nigra, fascia basali pallida ornata, iuferne 
subacumiuata ; columella lata, purpurea, superne macula lutes - 
centi notata. 
Longit. 19 mill., diam. 10. Apertura 7 longa, 6 lata. 
55 11 55 55 9. ,, 62 " ,, 5 „ 
The above measurements of two specimens from Fernando 
Noronha show tbe variation in the form of this variety. The 
white tubercles are rather acute in some specimens, whilst in 
others they are scarcely raised above the surface. On the body- 
whorl there are two approximated series at the periphery and 
two qbove, and at the base is a tesselation of white and dark 
spots. 
The shells quoted by Mr. Watson from Fernando Noronha are 
certainly specifically the same as those obtained by Mr. Bidley, 
and are, I think, almost specifically distinct from the L. nodulosa 
of d’Orbigny. They have less angular whorls and less acute 
nodules, of which there are two series on the body -whorl above 
the two principal series at the periphery, whilst in L. trochiformis 
(—nodulosa, d’Orb.) there is only a single series. The aperture, 
also, of the Fernando shells is darker and none of them exhibit a 
second pale zone at the upper part, which is nearly always visible 
in the West-Indian species. 
23. Littorina angulifera {Lamarck'). 
Litorina angulifera, Philippi, Abbild. vol. ii. p. 223, pi. v. ff. 12-15. 
JELab. West Indies, West Africa and Pacific (Phil.). 
Only a single young specimen was obtained by Mr. Eidley ; it 
agrees in all particulars with West-Indian' specimens. 
24. Torinia jethiops (Menke) . 
TIab. West Indies. 
Both Philippi and Hanley, in their respective monographs, admit 
this as a distinct species, but I am inclined to think with the 
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