KONOL. SV. VET. AKADEMIENS HANDLINGAR. BAND 25. N:<> 2. 87 



Stem-facet as in C. pugil, but the ends of the post. and r. ant. BB are more trun- 

 eated where the stein abuts on the T-piece. Both the T-piece and the i*, post. and r. ant. 

 R' enter more largely into the circumference of the stem-articulatioii. 



RR. — 1. ant. R: as in C. pugil; the inferradial is 2.75 mm. wide at the base, and 

 about 3.5 min. high; the superradial is about 4.25 mm. wide, and 1.25 mm. high. 



Large radials: as in C. pugil; but the 7th side, that abutting on IIBr 1} has come 

 more into a line with the 1st side, the articular facet, and may indeed be eovered by one 

 or other of the primibrachs. Side 1 is at right angles to side 6, as in C. }>"<jil, and at 

 a little more than a right angle to side 2, i. e. a less angle than in C. pugil. 



R' and r. ant. R' are as in C. pugil. 



The T-piece is not quite so much exeavated for the stem as in C. pugil; it has, 

 however, sunk further towards the stem-facet. In neither specimen does it appear to have 

 touclied any plates of the large side-arms. 



Anal structures: x rests on the T-piece, and, by its corners, on the r. post. and 

 f. ant. W. 



VYhen the arms are folded there are still scen two other plates and part of a third 

 following on .r; thns a much higher triangle of anal plates is seen than in C. pugil. The 

 visible portions of these plates also are flatter and seem to abut against the main-axils 

 rather than to be eovered by them; this appearance, however, is by no means so marked 

 as in C. ienax. 



Arms: 1. ant. bears about the same relation to the larger hrancb.es of the other 

 arms as in C. j>ii'jil- It is apparently simple. Its total length was 23 mm.: eight ossicles 

 are preserved; there was perhaps one more very small one. The first brachial is shaped 

 much as in C. pugil, but, since it abuts against the second as well as the first IlBr of 

 the adjacent arms, it has becoine eight-sided instead of six-sided. Its sides have a curi- 

 ously flattened appearanee. The succeding brachials are mostly rounded, not at all monili- 

 form, and usually a little higher than wide. Their articular surfaces are granular; their 

 ventral groove is a broad V, with a slight tongue for the axial cord; their section is more 

 circular than in C. pugil. 



The ant. and 1. post. arms follow the ordinarv law of branching, but the modifica- 

 tions seen in C. pugil are here intensified. The large outer armlets (gamma-brachs) of 

 eaeh axil-arm have increased in size, and all of them now form a fairly regular series, 

 gradually diminishing in length and thickness in each axil-arm. What are really the 

 niain axil-arms with their armlets are reduced in size and hidden by these larger armlets 

 to a much greater extent than is the case in typical forms of C. pugil; they can, how- 

 ever, be still seen when the arms are closed; their ossicles are much compressed, and 

 consequently very long in proportion to their width; their axillaries can be distinguished, 

 although the armlets springing from them are rarefy seen. The alpha-, and, to a less extent, 

 the beta-axillaries of each axil-arm are clearly scen, owing to the slight swelling of the 

 nodes and the slant of their sutures; this nodosity is rendered more consj)icuous than in 

 C. pugil by the snioothness of the rest of the arms. IBi^ is more triangulär than in 

 O. pugil: the two IBr together form a parallelogram, of which the diagonal almost coincides 

 with the suture between them: consequently only a small portion of lax abuts on the 



