D. BRYCE ON MACROTRAOHELOUS CALLIDIN^. 445 



single joint. Having regard, however, to the separate movements 

 of the toes and their presumable control by dififerent muscles, I 

 incline to consider that in reality there are two segments present, 

 at all events in those cases where there are either three or four 

 toes. The central single toe (or where there are four the central 

 pair) is protruded and withdrawn independently of the outer pair, 

 and usually distinctly beyond them. The central toe (or pair) is 

 probably, therefore, to be more correctly considered as proceeding 

 from the real terminal, the outer pair of toes from the penultimate, 

 and the spurs from the ante -penultimate foot joint. In the present 

 case the central pair of toes are stouter than the outer pair, and 

 broadly truncate. 



Callidina i^sseola^ Zelinka.® 



Sp. Ch. — Large and bulky. Body stout throughout, not 

 centrally swollen, but somewhat thickened at level of mastax and 

 at pre-anal segment. Yellowish-red to reddish. Corona large, 

 upper lip wide, with slightly convex margin, without lobes or 

 hillocks. Rostral lamellae stand apart to right and left of rostrum 

 tip. Skin stippled. Antenna short. Mastax with six salivary 

 glands attached. Eami longer than combined width, (31) against 

 (2 9 '4), formula j to ^. Vascular canals with eight vibratile 

 tags on each side. Mucus glands of foot built up each of three 

 series of cells. Foot short, of three joints in all, the second bearing 

 the spurs, and the terminal furnished with a perforate disc, of reni- 

 form outline on which arise two small prominences. Spurs short 

 (12), perforate at tips, and separated by wide (13), slightly convex 

 interstice. Maximum length (" 500 " Zelinka, '< 680 " Janson). 



In 1892 I found near Felixstowe a large Callidina, which I was 

 unable to identify then, but which I am now certain was this 

 species, which had been described in the previous year by Zelinka, 

 who has devoted much time to a searching investigation of every 

 detail of its anatomy and of its embryological development. The 

 most distinctive points in its diagnosis ar3 the form of the 

 upper lip, and the suppression or absence of the toes, these 

 being represented only by the two small prominences on the 

 disc of the terminal joint. In the rami is found a good 

 instance of the variation of the tooth-formula which obtains 

 in many species. The fine strise which, as usual, cover the 



