NO, 1704. A COLLECTION OF SHELLS FROM PERU—DALL. 293 



EXPLANATION OF PLATES. 



Plate 20. 



Page. 



Fig. 1. Polypus fontaineanus Orhigny, ]en^th 2n cm., nee 181 



Plate 2L 



Fig. 1. Lolujo gah I Orbigny, length 30 cm 181 



2. Endostyle of the same. 



Plate 22. 



Fig. 1. Conc/io?ep«.s co?ic/io?e;xrs Bruguiere, natural size 168 



2. Tliais chocolata Duolos, natural size 169 



3. Solenosieira fusiformis Blainville, natural size 167 



4. Thais kiosquiformis Duclos, natural size 170 



Plate 23. 



Fig. 1. Trochita frochiformis Gmelin, natural size, from above 175 



2, 5. Crepidula onyx Sowerb_v, natural size 174 



3. Bulimulus cokerianus Dall ; height 27 mm 164 



4. OHva peruviana Jjamarck, showing animal as contracted by alcohol, 



with the " pocket" at the posterior end of the foot turned inside 



out , 165 



6. Acanthopleura echinata Barnes, natural size, from above 180 



7. Littorina peruviana Lamarck, f natural size 172 



8. Enoplochiton niger Barnes, natural size, from above 181 



Plate 24. 



Fig. 1, 2. Acmxa viridula Lamarck, natural size 178 



3, 7. Megatehennus cokeri Dall, length 27.5 mm 178 



4. Tegula atra Lesson, natural size 176 



5, 6. Fissurella crassa Lamarck, interior and profile; length 50 mm 177 



Plate 25. 



Fig. 1. Mytilus chorus Molina, J natural size 151 



2. Palette of Xylotrya dryas, inside view, f 162 



3. Palette of Xylotrya dryas, outside view, f 162 



4. Mytilus magellanicus Lamarck, 5 natural size 151 



5,6,7. Xylotrya dryas DaW; 6, outside of left valve; 5, interior of the two 



valves conjoined; 7, interior of left valve, natural size 162 



8. Iphigenia alfior Sowerby, natural size 159 



9. Area (Anadara) grandis Broderip and Sowerby, umbonal view, 



natural size, of an adolescent specimen 154 



10. The same, in profile 154 



Plate 26. 



Fig. 1. Os^rea c/wZensis Philippi, interior of attached valve, i natural size... 148 



2. Ostrea columbiemls Hanley, interior of attached valve, natural size . . 149 



3. Anomalocardia subrugosa Sowerby, natural size 158 



4. Cyrena isocardioides Deshayes, natural size 159 



5. Pecten jnirpuratus Lamarck, ^ natural size 149 



6. Pecten purpuratus, part of the external sculpture, much enlarged... 149 



