1882.] ‘LIGHTNING’ AND ‘PORCUPINE’ EXPEDITIONS. 673 
He says it is ‘* uot an Acmeid,” and would place it near Caupulus ; 
but he qualifies his remark by saying that “it is barely possible it 
may be a Cocculina.” He is an unquestionably good authority on 
this as well as other departments of the Mollusca; and I venture 
with much hesitation to differ from him. 
ADDISONIA ECCENTROS, (EXCENTRICA) Tiberi. 
Gadinia excentrica, Tib. in Journ. Conch. vi. p. 37, pl. ii. f. 6. 
‘ Porcupine’ Exp. 1870: Atl. St. 16; Med. Adventure Bank. 
Two specimens. ; 
Distribution. Coral-fishery, Sardinia (Tiberi) ; a single specimen, 
with Gadinia gussoni. 
I have made a slight change in the specific name by substituting 
a classical word for one which is not Latin. 
This remarkable shell appears to be the Addisonia paradoxa of Dall 
(Proc. U.S. Nat. Mus. 1882, p. 405), which was dredged by 
Verrill off the New-England coast in 69-130 fathoms. Dall long 
ago pointed out that Tiberi’s species was not a Gadinia. Tiberi’s G. 
compressa (recent and fossil), of which through his kindness I possess 
specimens, is certainly a species of Lepetel/a, Verrill, and comes 
near L. tubicola, which has been lately found by G. O. Sars on 
the western coasts of Norway. Addisonia appears to be allied to 
Pilidium. See the above-cited ‘ Proceedings of the United-States 
National Museum’ for Dall’s excellent and elaborate paper on the 
families Cocculinide and Addisoniide, consisting of the genera 
Cocculina and Addisonia. The present species is not the Patella 
excentrica of Sandberger from the Mayence Basin. 
Although the genera Umbrella and Tylodina (which are closely 
allied) have a patelliform shell, there is a peculiarity in that respect 
which connects them with Aplysia and the Nudibranchs, viz. in the 
spiral and heterostrophe nucleus. Tylodina duebeni of Lovén occurred 
at Stations 24 and 27 of the ‘ Porcupine’ Atlantic dredgings in 1870. 
It seems rather strange that M. Gaston Moquin-Tandon, in his long 
and studiously exhaustive memoir on the Umbrella of the Mediter- 
ranean, did not notice this peculiarity, nor even assign or propose 
any place for that genus in the classification of the Mollusca, while 
he freely criticised all previous writers on the anatomy of the animal. 
» 1. Propripium ancyuorpes, Forbes. 
Patella ancyloides, Forb. in Aun. Nat. Hist. v. p. 108, pl. ii. f. 16. 
Propilidium ancyloide, B.C. iii. p. 254, pl. vi. f.1 5; (P. ancyloides) 
v. p. 200, pl. lviii. f. 7. 
‘ Lightning’ Exp., St. 5. 
‘Porcupine’ Exp. 1869: St. 1, 6, 13, 14, 19. 1870: Atl. 16, 
17, 17a; Med. Adventure Bank, 
Distribution. ‘Valorous’ Exp., Loffoden I. to Galway coast, 
Kimmeridge B. Dorset (Pleydell)?, Naples (Acton), Trapani, Sicily 
(Seguenza) ; 10-1450 fms. 
Fossil. Pliocene: Sicily. Post-tertiary: Christiania; 30-100 ft. 
Rostrisepta parva of Seguenza. 
45* 
