File:American malacological bulletin (1988) (18129757276).jpg

Title: American malacological bulletin
Identifier: americanmal6719881990amer (find matches)
Year: 1983 (1980s)
Authors: American Malacological Union
Subjects: Mollusks; Mollusks
Publisher: (Hattiesburg, Miss. ?) : (American Malacological Union)
Contributing Library: Smithsonian Libraries
Digitizing Sponsor: Biodiversity Heritage Library

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86 AMER. MALAC. BULL. 6(1) (1988) tegmentum ovate, wider than long, constricted anteriorly along jugum; sutural laminae very wide, flared anterolateral^, with straight anterior margins, separated by very shallow, broad, V-shaped sinus; 2 slits in posterior insertion plate small, nar- row, V-shaped. Jugum smooth, narrow, with parallel sides well- separated from lateral tegmental surface, extended anterior- ly beyond main tegmental mass. Tegmentum of all valves covered with small (100 ^m) round to slightly ovate pustules (Fig. 23), with single subcentral macresthete, 3-4 micresthetes. Girdle upper surface covered with dense mat of very small (60 ^m) spicules overlain by extensive patches of slender, straight, white spicules 400-500 /xm long (Fig. 24), especially evident posteriorly and where girdle intrudes be- tween valves; 18 anterior and sutural tufts containing 50-60 straight or slightly curved, stout, sharp-tipped green spicules up to 2.2 mm long; margin fringed with slender, sharp-tipped spicules up to 1 mm long, arranged in alternating groups of purple and white; underside densely covered with slender, sharp-tipped spicules about 80-90 /xm long, directed toward periphery. DISCUSSION: Acanthochitona ferreirai is related to A. hemphilli and, especially, to A. rhodea of the Caribbean region. The relatively shorter, wider valves, round to subovate tegmen- tal pustules, and dense, clearly evident patches of longer spicules on the dorsal surface of the girdle separate A. fer- reirai from the other two species. This is the species reported from the eastern Pacific as Acanthochitona rhodea by Keen (1958), A. G. Smith (1961), Thorpe (In Keen, 1971), Bullock (1974), and Ferreira (1985). Together, those authors reported specimens ranging from Mexico to Peru. I examined only specimens from Costa Rica and Panama, so I cannot confirm that specimens from Mex- ico and Peru are conspecific with the material described here. ETYMOLOGY: Named for the late Antonio J. Ferreira, whose work stimulated much interest in Caribbean and Panamic polyplacophorans. Acanthochitona spiculosa (Reeve, 1847) Figs. 25-29 Chiton spiculosus Reeve, 1847: pi. 9, sp. and fig. 47. Acanthochites spiculosus, Pilsbry, 1893: 22, pi. 13, figs. 60-62. (non Acanthochitona spiculosa of subsequent authors). TYPE MATERIAL: LECTOTYPE: 33.0 mm; "Loc. West Indies; Cum- ing collection; Acc. 1829"; BM (NH) 1981251/1 (herein designated). PARALECTOTYPES: 4 spec, 21.0-28.0 mm; collected with lectotype; BM (NH) 1981251/2-5. DISCUSSION: All five types (Figs. 25-29) at one time were glued to a tablet by either the dorsal or ventral surface. Three specimens contain the dried remains of the foot and viscera, and two have been scraped clean beneath. Within one of the latter, a tag was glued but has been removed, leaving only a torn remnant upon which no information remains. This specimen (BM(NH) 1981251/1), previously labeled as the figured syntype, is the most flattened and best preserved of the specimens and most resembles Reeve's figure 47 in its proportions of length and width; it is designated herein as the lectotype. However, if this is the specimen figured by Reeve, considerable liberties were taken to enhance the illustration. Reeve's figure depicts a black, smooth, shiny surface over all valves; each intermediate valve is drawn with a distinct jugal separation extending obliquely from the posterior beak to the anterolateral corners of the exposed valve surface; a single concentric band appears near the lateral margins of each valve. Spicules of dorsal tufts are depicted as long, densely packed, and fully spread from each cluster, overlying the entire girdle and extending beyond its narrow margin. The
Text Appearing After Image:
Figs. 25-29. Acanthochitona spiculosa (Reeve, 1847), type specimens, "West Indies". Fig. 25. Paralectotype, 27.0 mm; BM(NH) 1981251/3. Fig. 26. Paralectotype, 28.0 mm; BM(NH) 1981251/2. Fig. 27. Lectotype, 33.0 mm; BM(NH) 1981251/1. Figs. 28, 29. Paralectotypes, 26.0, 21.0 mm; BM(NH) 1981251/4, 5.

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