CRUSTACEA MALACOSTRACA. III. 



183 



Calathura Norm. & Stebb. 



This genus has been well characterized by the English authors and by G. O. Sars. — It may- 

 be emphasized that in the maxillipeds the first joint has completely disappeared, as already figured 

 by Sars. As to the statocyst in the telson see above p. 180. 



125. Calathura brachiata Stimpson. 

 (PI. XV, fig. 3 a). 



1854. Anthura brachiata Stimpson, Smiths. Contrib. to Knowl., VI, 1853, p. 43. 



1878. arctica Heller, Denksch. math, natur. Classe der Kais. Akad. Wiss. Vol. XXXV, p. 38; 



PL IV, figs. 9-12. 

 ! 1886. Calathura brachiata Norman & Stebbing, op. cit. p. 131 ; PI. XXVI, fig. 1. 

 ! 1897. — G. O. Sars, Account, II, p. 46; PI. XIX, fig. 2. 



! 1897. — norvegica G. O. Sars, op. cit. p. 45; PL XIX, fig. 1. 



This species varies extremely as to size, and the largest specimens are from cold localities. I 

 have compared a few large specimens with the somewhat small specimens from the "Ingolf" Stat. 32, 

 with the temperature 3 - 9°, and at first I thought I had found a difference in the shape of the telson, which 

 is narrower and more produced in the large specimens, but afterwards I found pronounced variation 

 among the specimens from Stat. 32. A female with young in the marsupium from this locality is 16-8 

 mm. long, another female with marsupium 18 mm., and the largest of the 41 specimens is 21 mm. A 

 specimen from the "Ingolf" Stat. 126, temp. -f- 0-5°, measured 39 mm., while my largest specimen, taken 

 in Scoresby Sound, East Greenland, 5 — 25 fath., is 45-5 mm.; Ohlin had a male measuring 43 mm. 



I have examined a co-type of C. norvegica G. O. S. presented by Sars, but was unable to see 

 the differences between this form and C. brachiata. Especially one of the dorsal impressions was well 

 developed, and the eyes seemed to be not more indistinct than in many specimens of C. brachiata; 

 probably both are blind, as no vestige of facets can be discovered. According to Sars, the adult female 

 of C. norvegica is 12 mm. long, but in spite of the difference in size I must agree with Ohlin and 

 Stappers, who after a careful examination cancelled C. norvegica. — On the statocyst (fig. 3 a) see p. 180. 



Some fifteen years ago I discovered in the marsupium of three specimens from Forsblad Fjord, 

 East Greenland, a most interesting parasite, which I believed must be an unknown genus of Cirripedia 

 Rhizocephala. Some years afterwards Dr. Geoffrey Smith worked out this material and found that 

 the parasite was a very aberrant type of Rhizocephala, and he established it (1906) as Duplorbis Ca- 

 lathura G. Smith. 



Occurrence. Taken by the "Ingolf" at thirteen stations. 



Davis Strait: Stat 32: Lat. 66°35' N., Long. 56°38' W., 318 fath., temp. 3-9°; 41 spec. 

 Stat 35: Lat. 65°i6' N., Long. 55°c>5' W., 362 fath., temp. 3-6°; 1 spec. 



Denmark Strait: Stat. 95: Lat. 65°i4' N., Long. 30°39' W., 752 fath., temp. 2-1°; 1 spec. 

 — — Stat. 96: Lat. 65°24' N., Long. 29°oo' W., 735 fath., temp. 1-2°; 1 spec. 



West of Iceland: Stat. 85: Lat 63°2i' N., Long. 25°2i' W., 170 fath.; 3 spec. 



South-West of Iceland: Stat 78: Lat 6o°37' N., Long. 27°52' W., 799 fath., temp. 4-5°; n spec. 



