KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 25. N:0 2. 31 



Anal Structures: R' is seven-sided, since it rests 011 three basals; hut when the upper 

 edges of these basals come into line it is five-sided. It varies in its proportions: in the 

 conical forms the breadth is as a rule verv little more than the height; in Pl. I, tig. 1 

 the height is 3.7") mm., the breadth 2.5 mm.: in the ovoid forms the breadth and height 

 may be equal; in one specimen the height is 2.7;") mm., the breadth 2.25 mm., but the 

 great curvature of the plate makes the breadth far less th;m it would be if the plate were 

 more flattened; the difference of proportion is therefore more apparent than real. The 

 apex is sometimes extended in a long thin process almost separating the two small radials, 

 as shown in de Koninck's fignre of P. ornatus. 



Anal x, as I eall the plate that rests on the truneate process between the right and 

 lett posterior radials, is rarely preserved in this speeies; a portion of it, however, is to be 

 seen attached to the process in a specimen from Petesvik, while it is shown, thongh broken 

 off from the process, in Pl. I, tig. 8. It appears to have been long and rather thin and 

 to have passed in between the arms rather rapidly: it is grooved on its inner side. 



The remainder of the tube is nnknown. 



The Tegmen is unknown; but in Pl. I, tig. 8 there are seen fragments of plates 

 attached by suture to the processes between r. post. R and r. ant. R, and 1. post. R and 

 1. ant. R. I am inclined to regard these rather as covering plates that have entered into 

 the tegmen than as orals. These covering plates appear to have rested on the sloping sides 

 of the spear-head, just as distichals rest on an axillary eostal, while the orals probably 

 rested between the covering plates and partly touehed the hollow inner margin of each 

 ])rocess; in the posterior interradins, however, the oral must have been pushed a little to 

 the centre and have been slightly hollowed on its outer side to allow for the passage of 

 the rectum. 



The Stem: In the type-specimen of P. flageihifer (Iconogr. Tab. IV, tig. 1, Pl. 1, 

 fig. 1) 12.5 mm. of stem are preserved: the proximal millimetre is slightly swollen, and 

 just below this the stem is broken: at the proximal end of the stem the ossicles are low 

 and alternate in size; distalwards they become equal and about 0.75 mm. high, with a 

 width of 1.25 mm. In K 652, Brit. Mus., 11 mm. of stem, somewhat broken, are preserved: 

 the ossicles are about 0.75 mm. wide, short and slightly moniliform. The axial canal is 

 very small and apparently round. The sutures are plain, not erenelate. 



Notes on Angelin's figures: 



Tab. IV, tig. 1, la: the trne length of this specimen is 51 mm.; it lies on the 

 matrix in the position of tig. 1; the aspect of fig. la is only visible in the lower part 

 of the cup, and for this part it is correetly drawn: the length of the arm-ossieles is ex- 

 aggera.ted; the shape of the proximal brachial is ineorrectly given: the shape of the stem 

 is fairly shown in fig. 1, bnt the ossicles themsclves are wrong: this specimen is refigured 

 in my Plate I fig. 1. 



Tab. IV, figs. 1 I) and 1 e: the sutures between the basals are a little too regularlv 

 spaced, otherwise these and tigs. 1 c and 1 d are fair representations. 



Tab. IV, tigs 1 </, 1 e and probably also 1 />, 1 c represent a rather large form from 

 the Klinteberg. All figures 1 represent the ovoido-conical form. 



