138 - MITRULARTA. 



M. Roissyi, Dufo, Lithedaphus longirostris, Owen, J/, dormiloria^ 

 Eeeve (fig. 60), 31. ossea, Reeve (fig. 39), M. Hipponiciformis, 

 Reeve (figs. 40, 41), 3L cijathella, Reeve (fig. 42), 31. bulla, 

 Reeve (fig. 43), 31. siultorum. Reeve (fig. 44), 31. Tongana, Quoy 

 (figs. 45, 46), 31. pjileopsis, Quoy (figs. 47, 48), 31. chlorina, 

 Gould (figs. 49-51), 31. radiosa, Gould (fig. 52). These forms 

 represent a great variet}" in shape and sculpture, and it is not 

 wonderful that, with the ideas prevalent among conchologists a 

 quarter of a century ago, they were described as distinct 

 species. I have, for convenience, separated a series of irregu- 

 larly corrugated forms as a variety, but they really connect 

 insensiblj' with the t3-pe. 



Yar. TORTiLTS, Reeve. Figs. 53-59, 61-67. 



Surface irregularl}' corrugated and folded, the folds longi- 

 tudinal, oblique or concentric, sometimes taking ever}' direction, 

 and so thick as to obscure the radiating striae. 



West Indies, Philippines. 



This form is ver}' usual, especiall}- in West Indian specimens. 

 31. diaphana (fig; 54), Reeve, 31. Martiniana, Reeve (fig. 55), 

 if. uncinata. Reeve (fig. 57), 3T.papyracea, A. Ad. (figs. 58, 59), 

 31. cornea, Reeve (figs. 61, 62), 31. cicatricosa. Reeve (fig. 56), 

 M. saccharimeta. Reeve 'fig. 63), 31. Balanoides, Reeve (fig. 64), 

 31. porosa, Reeve (figs. 65, 66), and 31. fihulata. Reeve (fig. 67), 

 are all synonyms. 



Yar. ACULEATA, Reeve. Fig. 70. 



Radiately striate and scaled, or short spinose. 



Honduras. 



31. tubifera, Gray (unfigured), from the same locality-, is doubt- 

 less a synonym. 



M. CORRUGATA, Brod. PL 43, figs. 68, 69. 



Suborbicular, apex subcentral, rugosely radiately ribbed and 

 striated, ribs scaly towards the margin ; whitish, or light yellow- 

 ish brown. Diam. 40 mill. 



Guacomayo, Central America. 



Found b}' Cuming, under stones at 14 fms. A beautiful form, 

 but perhaps not specifically distinct from 31. equestris. 



