64 



43. nebulosa, Conrad. 



44. occa, Reeve. 



45. perviridis, id. 



46. Pernoides, id. 



47. Peruviana, id. 



48. pica, Gould. 



49. Placunoides, Reeve. 



50. prretexta, id. 



51. producta, i^. 



52. pulchella, id. 



53. punctulata, itetfre. 



54. radida, id. 



55. reticulata, zW. 



56. rutila, id. 



57. Savignyi, Desk. 



58. scabriuscula, Reeve. 



59. scalpta, zW. 



60. semisagitta, Za?». 



61. signata, Reeve. 



62. smaragdina, id. 



63. spectrum, w?. 



64. sugiilata, id. 



65. Tarentina, iara. 



66. tegulata, Reeve. 



67. trocliilus, id. 



68. vexillum, z'<#. 



69. vitrea, id. 



70. zebra, w?. 



Figure. 



Avicula lata. PI. 28. Fig. 165. Shell, of a species intermediate in 

 form between the two Lamarckian divisions, Avicula and Meleagrina, 

 showing the linear position of the ligament. 



Genus 2. VULSELLA, Lamarck. 



Animal ; unknown. 



Shell ; longitudinal, equivalve, somewhat irregular, umboes equal ; 

 hinge-callosity in each valve prominent, depressed at the upper 

 part, and havitig an obliquely arched conical pit containing the 

 ligament. 



The Yidsella, of which the soft parts have not yet been observed, have 

 an extended tongue-like shell, like the lobeless Mallei, and they have a 

 similar hinge, the ligament being contained in a central spoon-shaped pit. 

 The umboes are, however, attenuated, and recede from each other so as to 

 form a kind of hooked area. Of sixteen species at present known the 

 shells present a great similarity of sculpture, all being more or less beset 

 with lamina? of minute crenulated scales. There is very little indication of 

 a byssus, and, like Crenatula, their habit is to live imbedded in sponge. 

 They chiefly inhabit the Red Sea. 



1. attenuata, Reeve. 



2. corollata, id. 



3. crenulata, Lam. 



4. hians, id. 



Species. 



5. Isocardia, Reeve. 



6. Limseforrnis, id. 



7. lingua-felis, id. 



8. lingulata, Lam. 



9. Mytiliua, Lam. 



10. phasianoptera, id. 



11. Pholadiformis, id. 



12. rudis, id. 



