440 D. BRYCE ON MACROTRAOHELOUS CALLIDIN^. 



The body-length is measured from the tip of the rostrum to the 

 tips of the spurs, when the Callidina is extended, as in crawling. 

 The width of the corona is taken across the two discs, of the collar 

 across the widest part immediately succeeding the bases of the 

 pedicles, of the neck at the narrowest point between the collar and 

 the first central, all in direct dorsal view, while the Callidina is 

 feeding. 



For greater accuracy and for convenience of comparison the 

 dimensions are calculated and stated in microns (1000 microns=: 

 1 mm.), and to avoid repetition of the symbol the figures are simply 

 placed within brackets. Thus (262) is to be understood as 262 

 microns=*262 mm. The small numbers following authors' names 

 refer to appended list of authorities. 



All the 10 species now to be described belong to that numerous 

 group which I have distinguished by the term Macro trachelous, as 

 indicating their common characteristic of a relatively short foot. 

 The first five species have not, I believe, been hitherto recorded 

 for the United Kingdom, and inasmuch as there does not exist, 

 as far as I can learn, any description in our language of any one 

 of them, I have thought it desirable to reproduce more or less 

 closely the original descriptions of the respective writers. The 

 remaining five species are new to science. 



Callidina tetraodon, Elir. 



Sp. Ch. — Body yellowish-white, only moderately trans- 

 parent. Eostral lamellae somewhat laterally projecting ; spurs (11 

 to 15) slightly longer than width of segment carrying them, and 

 seated upon cushion-like swellings. Kami (30 to 32), formula f . 

 Maximum length (620). 



Janson ^ gives these characters for a form assigned by him to the 

 above species, which was defined by Ehrenberg ^ in 1848 with the 

 very scanty description of : — Body hyaline, eggs white, four larger 

 teeth central on each ramus, length ^ line. 



The following supplementary details are added by Janson : — 

 Body of 15 segments, with, dorsally and ventrally, eight longitu- 

 dinal skinfolds. Hypodermis stout, milky white, slightly opaque ; 

 alimentary tract usually pale yellow. Foot very short, of three 

 segments in all. The corona, seldom to be seen unfolded, is 

 moderately large, and only a little exceeds the neck in width. 

 Upper lip notched. Head, with two fronto4ateral prominences, as 



