24 PROCEEDINGS OF THE ACADEMY OF [Jan., 



Recluz, in the Catal. Mar. Moll. Jap., p. 72, having before me then a 

 single specimen obtained by Mr. Frederick Stearns, now in his collec- 

 tion in Detroit. I at that time noted the differences between the speci- 

 men and N. draparnaudii Reel., but thought the former might be 

 abnormal. The large size of the umbilical lobe and the strong cord 

 around the umbilical crescent readily distinguish P. sagamiensis from 

 draparnaudii, effusa Swains., powisianus Reel., cwningianus Reel, and 

 other species of that group. 



CALYPTB^IIDJE. 

 Ergaea walshi (' Herm.' Rve.). 



This name Ergcea was originally proposed for a subgenus of Crepidula 

 (Crypto), comprising the species C. plana Ads. and Rve. (not Say) and 

 C. walshi 'Herm.' Rve. It was J. E. Gray in 1867 who raised the 

 group to generic rank, explained its morphology, and showed that it 

 is related to Calyptrcea. Gray's half-contemptuous estimate of the 

 inability of his conchological contemporaries to appreciate morpho- 

 logical problems, expressed in his paper of '67, 9 has been amply justified 

 by the history of this genus; for in the latest works it still remains 

 included in Crepidula Having reached the same conclusion inde- 

 pendently before reading Gray's paper, it was with some surprise that 

 I found that he had exposed the facts in the case. 



Ergcea is the end of a line of differentiation from Calyptrcea, parallel 

 in its evolution to that phylum of Crepidula represented by the flat 

 white slipper-limpets of the group of Crepidula crepidula Linne* (C. un- 

 guiformis Lam.) and C. plana Say. The two groups, arising from 

 diverse ancestors, have reached a superficially similar appearance, 

 by adaptation to growing inside other shells. 



Ergaa walshi ('Herm/ Rve.) has been taken by Mr. Hirase at 

 Fukura, Awaji Island (Xo. 1,443 of Hirase's register), and by Miss 

 Hartshorne at Hayama, on Sagami Bay. 



Amalthea conica Schum. Essai, p. 181, PI. 21, f. 4 (1817). 



Patella cassida Dillwyn, Catal. II, p. 1,037 (1817). 



Hipponyx australis Lam., Quoy and Gaim., Voy. Astrolabe, III, p. 434, 

 PI. 72, figs. 25-34 (1834). Not Patella australis Lamarck. 



This abundant and widespread species has been called Hipponyx 

 australis by writers on the Japanese fauna. Hedley has recently 

 shown that the Lamarckian species is a South Australian Capulus, a 



9 Proc. Zool. Soc. London, 1867, p. 740. 



10 Tryon, Manual of Conchology, VIII, p. 130 (1886); Fischer, Manuel de Con- 

 chyliologie, p. 758 (1885). 



