171 



t 



(Kr.). Hitherto found only in the Kara Sea, the Murman Sea, near Tromso (Norway) and 

 off the West-coast of Greenland, and the genus has been found only on Hipp. Gaimardii 

 M.-Edw. and Hipp, polaris (Sab.). 



REMARKS. The genus contains only two species. As, in spite of the most careful 

 investigation, the male has not been found, our knowledge is defective in an important point. 

 Judging from the structure of the female, the ovisacs, the larva and the pupa, the genus 

 comes very near to Sphceronella, and the only really good character appears to me to be 

 the rudimentary maxillipeds of the female. A biologically important character is that — as 

 stated above — it lives in the branchial cavity of Decapoda Oaridea, as the genus Homoeo- 

 scelis lives in the branchial cavity of Cumacea. 



Conspectus of the Females. 



The frame of the head is an almost regularly transverse oval and provided exteriorly on 

 each side with a very long list which proceeds from the centre of the lateral outline and runs 

 outward, and especially backward, in an oblique direction 1. Ch. mirabile H. J. H. 



In the frame of the head the foremost lateral angle is strongly produced, forming a 

 good-sized, fairly broad and not quite short projection, a large part of which is covered by 

 the skin, whereas the very long lateral, essentially backward running list mentioned in the 

 preceding species is wanting . . . . 2. Ch. Hansenii Giard and Bonnier (without description). 



I. Choniostoma mirabile H. J. H. 



(PI. X, fig. 5a— 5c; pi. XI, fig. 1 a— Ik.) 



Choniostoma mirabile H. J. Hansen, Dijmphna-Togtets zool.-bot. Udbytte, 1887 1 ), p. 271—78, Tab.XXIV, 



fig. 7 — 7h. 



— Giard and Bonnier, Bull.scient.de la France etde la Belgique, T.XX, 1889, p. 346, etc. 



— Giard andBonnier, Bull.scient.de laFr. et d. 1. Belg. T. XXV, 1895, p. 479. 



FEMALE. The specimen represented in fig. 5 a is 3-5 mm. in length, 4 mm. in 

 breadth ; its shape is described in the diagnosis of the genus. The smallest specimen found 

 is a young one, 1-35 mm. long and 1-28 mm. broad, thus a little longer than broad, almost 

 circular in appearance, and somewhat flattened like the adult. The area surrounded by the 

 frame of the head (fig. la) is regularly rounded, somewhat shorter than broad; the anterior 

 part of the frame is fairly narrow between the antennulae, scarcely rising above the surroun- 

 ding soft membrane and exhibiting outwardly only a very narrow list, while its broader 

 part (indicated by a dotted line) is covered by the skin. The lateral and posterior parts of 



*) Separate copies of my contribution were distributed in the beginning of July 1886, whereas the whole 

 volume with the resume appeared in 18u7. 



22* 



