KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 25. N:0 2. 139 



The original of fig. 13 eannot be found; but as this appears to have possessed neither 

 arms nor stem and was admittedly abnorma] in the construction of the ealyx, its absence 

 does not affect our recognition of the species. The peculiarity in its structure, if we as- 

 suine some degree of correctness in the figure, appears to have been the absenee of anal 

 x, or what is niore probable, its fusion with the posterior basal. 



The original of fig. 12 is very inueh weathered. The arms are löst after IV or VBr; 

 and the stem together with part of the IBB is broken off. 



This species heads Group II, as having departed less than the other species of the 

 group from the normal type. 



Description of the specimen. 



Dorsal Cup: general shape broadly conical; the sides concavely curved, at first 

 mak ing an angle of 26° with the vertical axis, and then changing in the middle of the radials 

 to 59°. The angle that the arms make with the horizontal is therefore about 30°, and 

 this is much the same as in the next species C. fnuticus, but here the slope does not start so 

 low down and arises in a niore gradual curve. The outline of the cup as seen from be- 

 low is roughly pentagonal; the interradial areas have a slight concave curve, but are not 

 nearly so depressed as in the two other species of the group (tig. 226). 



IBB o? indistinguishable and parti y broken away. 



BB 5; 4 are hexagonal, with short adjacent sides; they widen above, and their 

 greatest width is a little niore than their height. Post. B is heptagonal, and rises 

 rather high. 



RK 5; not so particularly low as Angelin's diagnosis would lead one to suppose. 

 They project as above described. The facet occupies 2 / 3 width of plate, and is almost 

 vertical. 



The Arms dichotomise at frequent intervals. Their ossicles have rounded backs, 

 and are wide, but not quite so wide as in C. distensus. 



IBr 3. IBr, is wedge-shaped, so that the arms rapidly bend upwards instead of 

 continuing the direction of the cup-walls. This constitutes another point of difference 

 between this species and C muticus. 



IIBr 3 or 4. 



Anal structures: x small, hexagonal, widening above and supporting three plates 

 of the tube (fig. 225). Above these plates the tube is broken off. Thus far the anal 

 area is of quite ordinary construction, and what Angelin meant by »Analia duo» I ain at 

 a loss to conceive. Could he possibly have called the posterior basal an anal? 



Notes on Angelin's figures: 



Tab. XXIII, fig. 12. This drawing is not happy, for the only differentiating cha- 

 racter that the specimen possesses has been not merely ignored but totally misrepresented, 

 viz., the curvature of the cup and arms. There is besides no reason to suppose that the 

 ventral tube ended so soon in a mere rounded excrescence. 



