PYCNOGONIDA. E 
The «oculiferous segment» of Wilson and the «Augensegment» of Bøhm is only another 
expression taken from the appellation of Krøyer, but applied to the whole of the first segment of 
the trunk. When Erichson uses the name of Kopf for this part of the body, it is exclusively with 
regard to the ambulatory legs and the comparing them to the limbs of the Arachnida, of which again 
the three last pairs were to correspond to the thoracical legs of the Insects, while all the correspond- 
ing segments were to form the thorax. 
Oculiferous tubercle (Zxber oculare), fig. I, 0. 
Krøyer: Øieknude (protuberantia ocularis); Sars: Øieknude (tuberculum oculiferum). 
On the dorsal side of the first segment of the trunk, in the middle of it, but more or less 
backward, is found a knob-like protuberance, the oculiferous tubercle. The shape of this knob is very 
different, varying in the different genera and species, growing from a low, rounded swelling to a 
height of almost the length of the trunk, and ending with a tapering point. It is not until the second 
larval stage of development that the oculiferous tubercle begins to be seen as an excrescence on the 
first segment of the trunk after this segment being distinctly separated. The eyes make their 
appennamcelprElor tortherocunliferons tubercle om thespottorthefirstisegmentrof the 
trunk, from which this latter rises, and during the growth of the tubercle the eyes are raised with 
it more or less, so that in the imago they are placed in a square round the tubercle, more or less distant 
from its top. The tubercle bears typically four single eyes, ocelli, but frequently the eyes are not, or 
only a little, developed, so that as well blind species as seeing ones may be found in the same genus 
(Colossenderts). 
Neck (c0o/lum), fig. I cZ. 
I have thought it best, like Sars, to keep this name for the middle part of the first thoracical 
segment, when it is more or less strongly marked off, as I regard this appellation as so little marked, 
that it is no necessary consequence to look upon or denominate as head the thickened part of the 
trunk lying before the segment in question. 
Foster aulkprocesstolkthettmrstisesmentttor them sertion on tletolvrseromslers 
(protuberantia pedis oviferi), fig. I apo. 
Sars: Halsfortsats (processus colli) til Fæste for de falske Fødder. 
This process originates from the under side of the first segment of the trunk just before the 
process of the trunk; it is very short, inconspicuous, and from its outer side or point arises the 
ovigerous leg. When the segment of the trunk is short, so that there is no neck, the palpi get 
"towards it, and in some genera (Co/ossenders) the palpi do apparently arise from the fore side of 
this process. 
Second segment of trunk (segmentum corporis secundunn), fig. 1 c?. 
Third segment of trunk (segmentum corporis tertium), fig. 1 3. 
Fourth segment of trunk (segmentum corporis guartum), fig. 1 c4. 
No synonyms are here necessary to explain the opinion of the authors as to these segments. 
It is a matter of course, and everybody agrees that they are homonomous with the first segment of 
trunk, or, at all events, with the large upper and hinder part of it. 
Caudal segment (segmentum caudale), fig. 1 sc. 
