Details of tagma I of Erugosquilla massavensis (Kossmann, 1880). A-C and F under macro-fluorescence settings; D, E under crossed polarized light. A. Ventral view of tagma I, appendages and eyes removed. A large central sclerotic plate might represent the anterior part of the hypostome. Antero-laterally the antennulae insert, postero-laterally the antennae insert. Anterior to the possible anterior part of the hypostome another sclerite is present, here referred to as the antero-ventral sclerite, probably associated with the eye segment. The arrow marks the anterior part of a small sclerite posterior to the possible anterior part of the hypostome (see also C). B. Dorsal view of tagma I. The rostral plate covers this area and is attached to the posterior region of the segment of the antennae. Between the eyes a small sclerotic bridge is developed. Posterior to this bridge an antero-dorsal sclerite is present, possibly part of the antennular segment. C. Close-up of the small sclerite marked by an arrow in A. It is situated right between the antennae. D, E. Compound eyes. D. Median view. E. Lateral view. F. Antennulae (median) and antennae (lateral); left: anterior view, right: posterior view. Abbreviations other than before: ads = antero-dorsal sclerite; ant = antenna; ant in = antenna insertion; atl in = antennula insertion; atr hy? = supposed anterior part of hypostome; avs = antero-ventral sclerite; ce = compound eye (insertion); sb = sclerotic bridge.