292 MAZATLAN UNIVALVES 
this form are sometimes seen faint radiating ribs, which are 
_ quite abnormal, and are perhaps due to the inconvenient shape 
into which the creature finds itself driven.* 
* As D’Orbigny seems to have confounded both species and synonyms in this 
family, the following account of his type specimens in the Br. Mus. (mostly dead 
shells) may be useful to students. His own names and synonyms are given in 
quotations : the numbers are those on the tablets. 
559, 560, ‘*C. rugosa =imbricata, Sow.” are the true Crucibulum imbricatum ; 
not C. rugosa, Desh. ' 
561, **C. rugosa, Desh.—tenuis, Brod.” is neither one nor the other; but= 
C. ?imbricatum, var. Broderipii, Proc. Zool. Soc. June, 1856. 
556, “*C. rugosa, Desh. = rudis, Brod.” is neither ; but appears the shell described 
in Proc. loc. cit, as C. ?? imbricatum, var. Cumingii. 
562, ‘‘C. tubifera, Less. = spinosa, Sow. = auriculata, Chem.” is the true Cruci- 
bulum spinosum; but quite distinct from Patella auriculata, Chem. which 
appears to be the W. Indian form of C, umbrella, Desh, =rudis, Brod. 
555, “C. quiriquina” is the dull, thick, spineless ? variety of Crucibulum spinosum, 
=Byronensis, Gray. 
857, **C. rugosa, Desh.” is an interesting intermediate form between the last and 
the next, of the shape of Scurria mitra, Less. ¢ Esch., and sometimes develop- 
ing a very few ribs. 
558, ‘‘C. rugosa — lignaria,”’ rightly named; the extreme form, like the large 
fossil Hipponyx. 
566, ‘*C. intermedia” is a Galerus, apparently distinct from any of Broderip’s 
species. 
565, “C, mamillaris, & C. lorica [Plichen] Brod is uot the Galerus mamillaris, 
but the Galerus unguis, Brod. 
567, ‘°C. pileolus” intermediate in character between Galerus and Trochita. 
---, C, Patagonica” is probably a variety of Crepidula dilatata; as also may 
be ---, ‘C. foliacea”’, in spite of its rugose surface. 
573, **C. protea” are probably dead specimens of Crepidula incurva, or C. onyx, 
or both. 
574, “‘C. protea” are perhaps C. nivea, as may be some of the specimens of C. 
Patagonica : but, along with the last, are too much worn for certain identification. 
The following additional particulars of Mr. Broderip’s species may also be use- 
fal to students. 
Galerus unguis is very small, conical, and dark coloured. G.sordidus appears 
a flatter, lighter variety of the same species. Mr. Cuming’s specimens are all 
covered with Bryozoa; but none of them shew any tendency towards the corrugs- 
ted exterior represented in the Zrans. Zool. Soc. pl. 28, f. 2, 
Galerus striatus is well distinguished by its strongly seulptured exterior. 
Crepidula marginalis is intermediate in characters between C. onyx and C. 
aculeata; having the external appearance of the former, with a thin waved deck 
more resembling the latter. 
Crucibulum serratum outside resembles Or. ?? imbricatum var. Cumingii: but 
within, it has a remarkably appressed and angular cup. It comes more close to 
Cr. pectinatum, Proc, Zool. Soc. June, 1556, 
