N79

Lamprocyclas maritalis Haeckel ventricosa Nigrini

Lamprocyclas maritalis ventricosa Nigrini, 1968, p. 57, pl. 1, fig. 9

DESCRIPTION

"Shell campanulate, rather thick-walled, rough. Cephalis trilocular with numerous small subcircular pores and a stout 3-bladed apical horn, 1 to 2 times the cephalis length. Primary lateral and dorsal spines continue as ribs in the thoracic wall and may become external, forming small wings. Collar stricture not pronounced.

"Thorax inflated conical with hexagonally framed, circular to subcircular pores, aligned longitudinally, 11-14 across the widest part of the segment. Lumbar stricture distinct.

"Abdomen inflated cylindrical, much larger than the thorax. Pores hexagonally framed, circular to subcircular, larger than thoracic pores, arranged in longitudinal rows, 3-9 (usually 5-9) in a vertical series, 11-14 on a half-equator.

"Peristome often small, but clearly differentiated, poreless, with numerous acute, sometimes forked teeth arising from its lower edge; sometimes teeth are rudimentary or absent. Subterminal teeth, on the abdomen just above the peristome, are divergent, small and thornlike...

"This subspecies is distinguished from Lamprocyclas maritalis maritalis Haeckel and Lamprocyclas maritalis Haeckel polypora Nigrini by its larger abdomen. At the lower limit of its abdominal dimensions, it grades into L. maritalis polypora, hence and arbitrary minimum abdominal breadth of 150 microns has been selected for L. maritalis ventricosa. In Indian Ocean material, Nigrini (1971) found that the average abdominal breadth of L. maritalis polypora is 123 microns (range 119-136 microns)." (from Nigrini, 1968).

DIMENSIONS

"Length of apical horn 54-81 microns, of cephalis 36-45 microns, of thorax 54-63 microns, of abdomen (excluding peristome and terminal teeth) 72-127 microns.

"Maximum breadth of cephalis 36-45 microns, of thorax 108-127 microns, of abdomen 156-193 microns." (from Nigrini, 1968).

REMARKS

1. Benson's (1966) description of L. maritalis (p. 475) probably includes specimens of L. maritalis polypora and L. maritalis ventricosa.

Plate 25, figure 6

N80

RECENT DISTRIBUTION 1. Nigrini, 1968, text-fig. 10; "Few along the coast of Central America (south of 11 degrees N) and South America, and extending westward in the regions of the North and South Equatorial Currents; rare or absent in all other samples examined...

"The distribution shown in text-figure 10 roughly corresponds to a plot of average abdominal size, based on 10 measured specimens of Lamprocyclas maritalis from each sample. In the area of few L. maritalis ventricosa the average abdominal breadth is >150 microns, whereas it is <150 microns in the area of rare or absent L. maritalis ventricosa.

2. Molina-Cruz, 1975, Code N16; counted together with L. maritalis polypora and used in factor analysis of southeast Pacific assemblages; cf. Appendix 10 for percent N16 at each station.