450 D. BRYCE ON MAOROTRACHELOUS CALLIDIN^. 



Callidina j)lena, n. sp. (PI. XXIV., Fig. 4.) 



Sp. Ch.— Moderately large and robust. Skin smooth, dorsal 

 folds faint, lateral strong. Corona very wide (73), one-half wider 

 than collar (50) ; upper lip with two low conical lobes, separated 

 by shallow, broadly V-like groove. Rami (19), with thin wing- 

 like outer expansion of rounded outline, giving total breadth (25), 

 the rami proper totalling about (17) ; formula 2+\ ^+2. Foot 

 with four joints, in length about (40), or one-eighth of whole; 

 spurs short cones (6) with narrow interstice ; toes four. Stomach 

 wall lined with cilia, driving the food in a spiral course. Maximum 

 length (380), average (340). 



When crawling about this species resembles very much Call, 

 musculosa, but when it pushes forth its corona and begins 

 to feed it assumes somewhat of the compact and apparently 

 stout form of Call, quadricornifera. Like that commoner 

 form, however, it is then much flattened, and the ap- 

 parent bulk is deceptive. It is readily distinguished by the 

 great width of the corona as compared with the collar and with 

 the body length, a strong character well supported by the 

 modelling of the upper lip, the feeding position, the small spurs, 

 and the four toes. The planes of the two discs do not coincide, 

 but incline somewhat obviously to the median line. The upper lip 

 is so prominent that the conical lobes attain the level of the discs at 

 their inner side. Thus the whole breadth is approximately flat. 



The three cervical segments are all short, especially the first and 

 second, whilst the second, third, and fourth central are rather longer 

 than usual. In the feeding position the whole of the second 

 cervical and part of the first is hidden within the third, and of the 

 foot only the spurs and part of the first joint are visible. The first 

 foot joint is of fair length, but the second is short, and the third 

 almost indistinguishable. The four toes are, as usual, in two 

 pairs, of which the outer pair are larger than the inner. One tooth 

 on each ramus is exceedingly faint. 



I have found this species in great numbers in wall moss from 

 Aldwick, near Bognor, and I was able also to identify certain eggs 

 as pertaining to it. These were not truly oval, but a little 

 flattened, and the surface bore many low rounded prominences, of 

 which I counted 14 to 18 around the peripheral outline. As they 

 lay on their sides these eggs measured (76 to 85) longest by (50 to 

 54) shortest diameter, and I estimated their thickness at about 



