Conchoecia dichotoma

Müller, 1906

Diagnosis
Carapace of female with height about 50% of the length with strong anterior taper (C. dichotoma Habitus 1). Dorsal margin is almost straight because of slight development of the shoulder vaults. The postero-dorsal corner a blunt right-angle. The posterior margin curves smoothly into the ventral margin. Sculpturing, very faint parallel lines in the anterior ventral region. The left asymmetrical gland opens at the postero-dorsal corner; the right asymmetrical gland at quarter height up the posterior margin. Large groups of supplementary glands open on the right valve just dorsal of the right gland, and on both shells near the postero-dorsal corner. The male carapace similar in shape but small height : length ratio smaller, shoulder vaults slightly more developed (C. dichotoma Habitus 3).
Female, frontal organ clearly differentiated, stem projecting well clear of first antenna (C. dichotoma 1). Capitulum slightly S-shaped, finely spinous along the ventral surface, end pointed. First antenna with clear segmentation, second podomere with long dorsal seta extending well beyond the end of frontal organ stem. The sensory setae are ca. 40% the length of the "e" seta, one with swollen base.
Male, frontal organ, stem same length as first antenna, capitulum slightly curved, down-turned, with rounded end (C. dichotoma 3). First antenna, "a" seta long with a double swelling at base, "c" seta similar in length to second podomere, "b" seta longer than "d", "e" seta armature (C. dichotoma 4) about 30 pairs of small broadly flanged, closely-set, spines distal of which the seta is flattened into a sword-shape. Second antenna endopodite, the longer setae are flattened, one sensory seta swollen. The right-hand hook appendage bends sharply through 135°near its base, then distal to its straight shank it bends through a further 45° to end in a slightly swollen knob sometimes armed with a fine spine (C. dichotoma 5). The lefthand hook appendage is straight beyond the basal angle of about 100°.

Remarks
This is a relatively poorly-known species which Poulsen, 1973 placed in his new genus Paramollicia. The many inconsistencies between Poulsen's brief description and Müller's original description, makes it doubtful if his material was conspecific.

Distribution
Reported from all oceans. 60°N-42°30'S in Atlantic. Bathypelagic in its bathymetric range. 1, 2, 3 (R.R.S. Discovery Map).

Type specimens
None designated; status of original material uncertain.

Type locality
Original material described from near the equator both in the Atlantic (23°6'S 3°27'E) and the Indian Oceans (9°6'N 53°41'E).

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