KONGL. t>V. VHT. AKADKIMIKNP ITANUI, INGÅR. BAND. 22. N;<i 7. 45 



Tluwmoiis pcllHcidii,K.\.\\UAA']MO'ÉS-^\j\m. IH14. »On a iiow genus of Aiiiphi 



pod CrastiiucaiiS". 1'liil. 



Träns. Roy. Soc. Loiid. 



Vol. 163, p. 629 and 6.37, 



pl. 49 and .50. 

 » » » .1. S. KrNGsi,EY. IHHi. The Standard Natural Hi- 



story. Vol. 2, p. 74, Hg. 99. 

 'riiauiimlups " » C. BovALLlus. 188IJ. "Remarks on tlie genus Cy- 



steosoma or Thauraatops». 



Bill. t. K. Sv. Vet. Ak. 



Handl. Bd. 11, N:o 9, 



p. 8. 

 » " » >> 1S87 . "Systematical list of the Ara- 



phipoda Hyperiideai). Bih. 



t. K. Sv. Vet. Ak. Handl. 



Bd. 11. N:o 16, p. 14. 



Stkbbing dcscribes in an exliaiistivc luanner two of thc eii>ht spccimens collected 

 during the Challcnger-Expeditioii, a iiiale and a female; of the reiiiairiiug six he poiiits 

 out t.Avo as possibly distinct species viz: »Cystisoma, specinien i'^», which, if established 

 as a species by itself, he would call C. Parkiiisoni, and »specimen 6'», which even- 

 tually ought to be named C. Fabricii. The former coraes very near to Thaumatops 

 longipes, the latter resembles Thaumatops Lovéni in the shape of the metacarpus 

 of the last pair of peraiopoda, in other respects it seems to be closer connected with 

 Thaumatops spinosa. The tabular view below (p. 58) will show the measurements of 

 the hitherto known specimens, as far as I have been able to pick them up from de- 

 scriptions and drawings. These measurements will prove, I suppose, that there is closer 

 relationship between Thaunaatops spinosa and Th. longipes than between Thauma- 

 tops Lovéni and the two mentioned species. 



Here follows description onl}' of Guérin-Méneville's specimen extracted from his 

 diagnosis and drawing. 



For a full account of the species I refer to the above quoted woi-k of Stebbing. 



The head is broader and deeper than the pera^on, obtusely egg-shaped, almost 

 as long, the first tive peneonal segments together, measuring 25 mm. in length. From 

 the bases of the antennas runs on each side a row of 13 small teeth or spincs; on the 

 under side of the head there is another row of small spines on each side. 



The jirst pair of antennce are three-jointed, the last joint the longest; they are 

 shorter than the head, 15 mm. long. 



The segments of the perceon are high, inflated, the first and second are coalesced, 

 longer than the third segment. The fourth, fifth and sixth segments are equal in length, 

 the seventh longer, but shorter than the coalesced first and second, and shorter than the 

 first pleonal segment. The}^ show all a sharp median keel along the dorsal side, with two 

 spine-like prominences on each segment, except the seventh which bas three. 



The epimerals are coalesced with the lateral parts of the corresponding segments. 



Stout branchial säcks are attached to the fourth to sixth pairs of perteopoda. 



