AHF-PUB-PE-20-02~12 |
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184 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 20 Reinhart, 1943, p. 30), but the type must be examined to settle the question properly. Although Palmer (1951) lists Byssoarca vespertilio (no. 192) as present among the first duplicate series of the Reigen Mazatlan Collection deposited by Carpenter in the New York State Museum in Albany, it has been impossible to locate the sample in the Museum. Byssoarca fusca, reported from Mazatlan by Carpenter (1856a, p. 140), might perhaps be Barbatia lurida also. The shells at hand have a white ray radiating from the umbo, similar to that of the Caribbean species Barbatia cancellaria (Lamarck). The periostracum fits the description of Byssoarca vespertilio given by Carpenter (1856a, p. 141), and is soft and lamellose anteriorly. The bristles may be more or less worn off, especially on the median part. Small and large eye-spots are present around the whole mantle margin. The posterior part of the mantle margin is especially heavily pigmented. Also pigmented are the foot, the anal region, and the posterior part of the gills. The abdominal sense organs are of the same type as those of "Barbatia barbata" (= cancellaria (Lamarck) 1819) (Heath, 1941, Pl. 5, fig. 10). Measurements of the largest specimen in the present collection (1737-49) are length, 38.6 mm; height, 21.5 mm; diameter, 17.2 mm. Occurrence: Rather rarely taken in the intertidal zone down to 12 fms, attached to rocks. Distribution: Isla Espiritu Santo, Gulf of California, to Zorritos, Peru (the Peru locality reported by Olsson, 1924). The Galapagos Islands (one valve in the present material). Subgenus CUCULLAEARCA Conrad 1865 Cucullaearca Conrad, Amer. Jour. Conch., vol. 1, 1865, p. 11. Type of subgenus: Byssoarca lima Conrad 1847. (Subsequent designation by Stoliczka, 1871, p. 340) Remarks: The main characters distinguishing this group from Barbatia s.s.j according to Reinhart (1935), are a wider ligamental area, larger byssal gape, and posterior enlargement in outline. A posterior enlargement in outline cannot be used as a subgeneric character, as the form is extremely variable. According to Heath (1941), who had only a few species for examination, the anatomy did not show any distinguishing characters between Barbatia s. s. and Cucullaearca.
Object Description
Description
Title | AHF-PUB-PE-20-02~12 |
Type | texts |
Format (imt) | image/tiff |
Contributing entity | University of Southern California |
Filename | AHF-PUB-PE-20-02~12.tiff |
Full text | 184 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 20 Reinhart, 1943, p. 30), but the type must be examined to settle the question properly. Although Palmer (1951) lists Byssoarca vespertilio (no. 192) as present among the first duplicate series of the Reigen Mazatlan Collection deposited by Carpenter in the New York State Museum in Albany, it has been impossible to locate the sample in the Museum. Byssoarca fusca, reported from Mazatlan by Carpenter (1856a, p. 140), might perhaps be Barbatia lurida also. The shells at hand have a white ray radiating from the umbo, similar to that of the Caribbean species Barbatia cancellaria (Lamarck). The periostracum fits the description of Byssoarca vespertilio given by Carpenter (1856a, p. 141), and is soft and lamellose anteriorly. The bristles may be more or less worn off, especially on the median part. Small and large eye-spots are present around the whole mantle margin. The posterior part of the mantle margin is especially heavily pigmented. Also pigmented are the foot, the anal region, and the posterior part of the gills. The abdominal sense organs are of the same type as those of "Barbatia barbata" (= cancellaria (Lamarck) 1819) (Heath, 1941, Pl. 5, fig. 10). Measurements of the largest specimen in the present collection (1737-49) are length, 38.6 mm; height, 21.5 mm; diameter, 17.2 mm. Occurrence: Rather rarely taken in the intertidal zone down to 12 fms, attached to rocks. Distribution: Isla Espiritu Santo, Gulf of California, to Zorritos, Peru (the Peru locality reported by Olsson, 1924). The Galapagos Islands (one valve in the present material). Subgenus CUCULLAEARCA Conrad 1865 Cucullaearca Conrad, Amer. Jour. Conch., vol. 1, 1865, p. 11. Type of subgenus: Byssoarca lima Conrad 1847. (Subsequent designation by Stoliczka, 1871, p. 340) Remarks: The main characters distinguishing this group from Barbatia s.s.j according to Reinhart (1935), are a wider ligamental area, larger byssal gape, and posterior enlargement in outline. A posterior enlargement in outline cannot be used as a subgeneric character, as the form is extremely variable. According to Heath (1941), who had only a few species for examination, the anatomy did not show any distinguishing characters between Barbatia s. s. and Cucullaearca. |
Archival file | hancockunpub_Volume23/AHF-PUB-PE-20-02~12.tiff |