292 MAZATLAff UNIVALVES 



this form are sometimes seen faint radiating ribs, which are 

 quite abnormal, and are perhaps dne to the inconvenient shape 

 into which the creature finds itself driven.* 



* As D'Orbigny seems to have confoT aded 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. 



659,560, "C. rugosa = imbricata, Sow." are the true Crucibulum imbricatum ; 

 not C. rugosa, Desk. 



561, "C. rugosa, Desk. = tenuis, Brod" is neither one nor the other; but = 

 C. ? imbricatum, var. Broderipii, Proc. Zool. Soc. June, 1856. 



556, "C. rugosa, DesTi. = rudis, Srod." is neither ; but appears the shell described 

 in Proc. loc. cit. as C. ?? imbricatum, var. CumingiL 



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, Desk. = rudis, Brod. 



555, "C. quiriquina" is the dull, thick, spineless ? variety of Crucibulum spinoauia z 



557, "C. rugosa, Desk." is an interesting intermediate form between the last and 

 the D-exfc, cf the sliape of Scnrria mitra, Less. 4" -Eseft.j and sometimes develop- 

 ing a very few ribs . 



558, "C. rugosa lignaria," rightly named; the extreme form, like the largo 

 fossil Hipponyx. 



566, "C. intermedia" is a Galerus, apparently distinct from any of Broderip'a 

 species. 



565, "C. mamillaris, & C. lorica [Plichen] Srod." is not the Galerus mamillaria, 

 but the Galerus unguis, Srod. 



567, <C 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- 

 ful 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 Eryozoa ; but none of them shew any tendency towards the corruga- 

 ted exterior represented in the Trans. Zool. Soc. pi. 28, f. 2. + 



Galerus striatus is well distinguished by its strongly sculptured exterior. 



Crepidula marginally 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 Cr. PPimbricatura v*r. Cumin gii : but 

 within, it has a, remarkably appressed and angular cup. It comes more close to. 

 Cr. pectinatum, Proc. Zool. Soc. June, 1856. 



