Researches on the Visual Organs of the Trilobites

Text Emphasis denoted as _Italics_ and =Bold=. Magnificatons as 30/1. The » is used in Swedish for quotes and dittos. Numeric abbreviations N:o, 1:o, 2:o, etc. for Number, primo...

4. Hypothetical figure as a further development, following upon the stage represented in fig. 3. Fusion completed between all posterior plectra (2, 3, 4), thus forming a single...

This development can be followed in detail through the excellent figures of the larval stages of Sao hirsuta which BARRANDE has given in his magnificent work, vol. I, pl. 7. In...

In scrutinizing a horizontal, somewhat extensive section of an eye in this group of trilobites, it will be perceived, as for instance in the figures (Pl. V fig. 16, 22) that the...

A rolled up specimen from Andrarum Scania was sectioned lengthwise. The tail-piece closed tight against the head-shield, so there had been little chance for foreign matter to pe...

This species, of which only the hypostoma is known, found at Lansa, Gotland, is likely, to judge by that, to be nearly related to Br. polyactin. The shape of this hypostoma is e...

Commonly this species has been ranged with Phacops, but it is evident that it as to the conformation of its glabella and the head in general is highly discrepant, and in these r...

The hypostoma is in so far deviating that the terrace lines have a nearly vertical direction and in this respect much resemble those of the Phillipsiæ and the Proeti. The maculæ...

The position of the hypostomic eyes on the ventral surface of the trilobites is not quite so abnormous, nor so isolated a feature amongst the crustaceans as might at first be su...

Fig. 1. Horizontal section of cephalic eye near the inferior margin 60/1. _a_ surface of the eye, _b_ frame with irregular or reserve prisms, _c_ part of the cheek with normal s...