On the lateral borders of the hypostoma there are short spines, two on each side, but they are placed differently on the specimens and even wanting in some. The elongated, elliptical maculæ bear in their lower end a white spot on which is seen a little cluster of a varying number of small, segregated ocelli, from three to five, according to the different specimens, like so many black points. The maculæ attain the exceptional length of 4,7 millim. in some specimens, but commonly only 2 millim. We have as yet not been able to detect these remarkable ocelli in any other species of Proetus.
Ptychoparia Corda.
Walcott in »Palæontology of the Eureka District», gives on plate X fig. 21 a representation of a hypostoma which near the posterior margin shows two maculæ as narrow, crescentlike ridges and above them two longer and thicker ridges directed obliquely toward the central axis of the hypostoma.
Ptychopyge Ang.
Previous figures of hypostomas with maculæ are the following:
Pt. aciculata Br. II, pl. 1 fig. 13.
Pt. glabrata Br. II, pl. 1 fig. 14.
Pt. aciculata Ang.
The broad hypostoma bears the elongated, acuminated maculæ in an oblique direction, contrary to what is seen in most other species. The anterior end slopes inwards and the lower end outwards, the surface, which in the cast drawn is surrounded by a marginal line, is directed sidewards against the broad lateral wings and is obscured by the declivity formed by the groove. The same disposition of the mature also occurs in Ptych. glabrata. These two species consequently in this respect differ essentially from the other four species which we have examined, but there is for the rest no reason to make these form different genera or subgenera.