Plate 1 Issued from : W. Giesbrecht in Systematik und Faunistik der Pelagischen Copepoden des Golfes von Neapel und der angrenzenden Meeres-Abschnitte. - Fauna Flora Golf. Neapel, 1892. Atlas von 54 Tafeln. [Taf.46, Fig.7]. As Thaumaleus thompsonii.
Female (from East of Langeland, Baltic Sea): 7, habitus (lateral).

Plate 2 Issued from : W. Giesbrecht in Systematik und Faunistik der Pelagischen Copepoden des Golfes von Neapel und der angrenzenden Meeres-Abschnitte. - Fauna Flora Golf. Neapel, 1892. Atlas von 54 Tafeln. [Taf.46, Fig.27]. As Thaumaleus thompsonii.
Female: 27, A1 (ventral view).

Plate 3 Issued from : W. Giesbrecht in Systematik und Faunistik der Pelagischen Copepoden des Golfes von Neapel und der angrenzenden Meeres-Abschnitte. - Fauna Flora Golf. Neapel, 1892. Atlas von 54 Tafeln. [Taf.46, Fig.31]. As Thaumaleus thompsonii.
Female: 31, urosome (dorsal).

Plate 4 Issued from : W. Giesbrecht in Systematik und Faunistik der Pelagischen Copepoden des Golfes von Neapel und der angrenzenden Meeres-Abschnitte. - Fauna Flora Golf. Neapel, 1892. Atlas von 54 Tafeln. [Taf.46, Fig.36]. As Thaumaleus thompsonii.
Female: 36, P5.

Plate 5 Issued from : W. Giesbrecht in Systematik und Faunistik der Pelagischen Copepoden des Golfes von Neapel und der angrenzenden Meeres-Abschnitte. - Fauna Flora Golf. Neapel, 1892. Atlas von 54 Tafeln. [Taf.46, Fig.40]. As Thaumaleus thompsonii.
Male: 40, urosome (ventral).

Plate 6 issued from : G.O. Sars in An Account of the Crustacea of Norway, with short descriptions and figures of all the species, 1921 a, 8. [Pl. XII].
Female and Male (from Norway).

Specific characters of female : Body comparatively more slender than in Cymbasoma rigidum, with the cephalic segment narrower and considerably exceeding in length the remaining part.
Tail very short, scarcely longer than the last 2 trunkal segments combined.
Eye well developed.
A1 scarcely attaining 1/3 of the length of the cephalic segment, and of a structure very similar to that in C. rigidum.
Oral tubule somewhat more approximate to the frontal part of the head.
Genital segment unusually tumid, seen dorsally almost circular in outline, ventral trace strongly protuberant ; ovigerous spines of moderate length ; distal segment without any traces of lateral notches.
Caudal rami rather small, each provided with 3 subequal setae, no appendicular bristhe present.
Natatory legs with the outer ramus considerably longer than the inner, and the terminal segment more produced than in C. rigidum.
Last pair of legs resembling in structure those in C. rigidum, though having the innermost of the apical setae rather smaller and the lobe of the inner edge less prominent

Plate 7 Issued from : T. Scott in Rep. Fishery Bd Scotl., 1902, 20 (3). [Pl. XXV, Figs. 5-6].
Male (from Lerwick Harbour, Shetland): 5, habitus (dorsal); 6, P5.

Nota: The first of the two abdominal segments is shorter than the second.
Caudal rami each with 3 setae.

Plate 8 Issued from : T. Scott in Rep. Fishery Bd Scotl., 1904, 12 (3). [Pl. XIII, fig.1]. As Thaumaleus thompsoni. With doubt.
Female (from Lerwick Harbour, Shetland): 1, habitus (dorsal).

Nota : Cephalothorax about equal to twice the entire length of the remaining segments of the thorax and abdomen combined.

Plate 9 ssued from : T. Scott in Rep. Fishery Bd Scotl., 1904, 12 (3). [Pl. XIII, figs.2-4]. As Thaumaleus thompsoni. With doubt.
Female: 2, A1; 3, P5; 4, abdomen and caudal rami.

Nota : A1 shoprt and stout, appear to consist of 4 segments, but the 3rd, which is small, seems to be partly coalescent with the 2nd.
P5 moderately large, foliaceous, and abruptly wider at the distal extremity, the result of a lobe-like process on the inner distal aspect ; each foot carries 3 apical setae, the innermost of which is considerably shorter than the other two.
Abdomen 2-segmented ; 1st segment fully half as long as the last segment of the thorax, and large rand more dilated than the 2nd segment.
Caudal rami short, carry 3 moderately elongated setae.

Plate 10 Issued from : Suarez-Morales in Mitt. Mus. Nat. kd. Berl., Zool. Reihe, 2002, 78. [p.95, Table 1].
Comparison of main taxonomic features in species of Cymbasoma with a cephalothorax relative length equal or over 60%, females only: C. thompsoni Giesbrecht, 1892.
Mouth position way back anterior part of forehead in percentage of the cephalothorax length.
Compare with C. bowmani, C. boxshalli, C. longispinosum, C. morii, C. nicolettae, C. quintanarooense, C. striatus, C. tumorifrons, C. sp. (from Brazil), C. chelemense.