634 
DR. RUDOLPH YON WILLEMOES-SULIM ON A 
good state of preservation for figuring. All the eggs seemed, as might have been 
expected, to be in nearly the same stage of development, and I could not determine 
whether the spherical organ (“ kugelformiges Organ ” of the Germans) makes its 
appearance or not. 
Systematic Position and Affinities. — We have already pointed out so many rela- 
tions between the Crustacean described and Phronima , that no room is left for doubt 
that it is an Amphipod, although an aberrant one. We must now consider the 
characters in which the new genus differs from Phronima as well as from the Am phi- 
pods in general, and the position which must be assigned to it in the system of classifi- 
cation. I have only a very small part of the literature of the Amphipoda to refer to ; 
but the form and the anatomical structure of this genus is so remarkable, that I think, 
had it been previously described in detail, either Professor Wyville Thomson or I 
must have seen a figure of it. As this is not the case, I venture to introduce it to 
science with the following generic characters under the name of 
Thaumops, gen. nov. 
Caput oblongum, inflatum, oculis maximis superiorem capitis partem tegentibus. 
Segmenta thoracica 6, abdominalia 5. Antennarum in feminis par unum, maxil- 
larum par unum, pedum paria duo minima maxillarum locum tenentia. Mandi- 
buke nullae. Pedes thoracici 5, abdominales 3 in quoque latere. Appendices 
caudales 4. Gangliorum pectoralium paria 5, abdominalium 3. 
Thaumops pellucida, sp. nov. 
Corpus longitudine 84 mm., latitudine 21 mm., pellucidum. 
Locality. A single specimen of the female taken with the trawl from a depth of 1090 
fathoms off Cape St. Vincent. 
The segmentation of this genus presents only a very slight difference from that of 
Phronima , in which there are seven thoracic segments, while in Thaumops six only can 
be clearly discerned ; but, as I have already observed, the second segment is larger than 
the others, and bears two pairs of limbs — the second pair of maxillipeds and the first 
pair of ambulatory legs. It is therefore probable that this segment represents two seg- 
ments fused, in which case the segmentation of Thaumops would differ in no essential 
particular from that of Phronima. 
The shape of the head and of the eyes in Thaumops is very peculiar, and so is the 
position of the antennas. In the presence of a single pair only of antennae, and in the 
antennae being composed of two joints, Thaumops agrees with the female of Phronima ; 
but in the former genus the antennae are placed on the front of the head, while in the 
latter their place of attachment is close to the mouth. 
1 he number of the joints of the legs is the same in both forms; for if we recognize 
the two pairs of maxillipeds as legs, we have in both Crustaceans seven pairs in the 
