K.UKGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 59. N:0 4- 11 



P : — P 3 without sexual products, more slender. Pi(on II Br 2) 35 — 40 (the seg- 

 ments are covered with skin and therefore indistinct), 15 mm. P 2 13 ram, P 3 8 mm. 

 P 4 — P ]5 toi9 with about 25 segments, whieh are as long as they are broad. These are 

 the genital pinnules, which are thick, coarse and have their proximal ( ; ? /a) parts very 

 much strained by the sexual products. The 7 distal segments with strong hooks, 

 3 on each segment. Remaining segments with smaller, more irregularly arranged 

 spines. 



The tips of the pinnules turbinated, provided with a short comb with about 

 6 large teeth. 



P J( , etc. 11 mm, again more slender, composed of about 25 segments. These 

 very long (length as much as 3 times the breadth) at least in the proximal part. 

 The distal hooks only developed on the 3 last segments. Here and there terminal 

 combs with 6 — 10 teeth; these appear both among the genital and distal pinnules. 



Colour of the specimen kept in spirit: division ossicles dorsally brown; have 

 yellow spöts. The dorsal side of the Br:s have two yellow bands along the arms. 

 Remaining parts of the animal dark-brown. 



I have referred both the specimens described above to C omaster typica chiefly 

 on account of the construction of Cd and development of the C:i. The specimens of 

 C. multifida described below differ very considerably in these two characters, and 

 as I have both a young and a mature specimen where Cd and the C:i are of the 

 C. typica-iorm, I do not hesitate to refer these specimens to this, though the num- 

 ber of the arms is smaller and the method of ramification differs from the normal 

 typica. Perhaps it might be possible in this case to suggest a form »minor». 



A. H. Clark has obtained a classification of the methods of different articula- 

 tions between the segments. There are muscular articulations either in straight or 

 oblique joints, and also non-muscular connections divided in syzygies and synarthries. 

 For a more detailed description of the function and development of these ef. Clark 

 op. cit. 9, p. 113 ff., and op. cit. 22, p. 587 ff. Here I will only mention that syzy- 

 gies may replace synarthries and thus be transformed in direction to. the syzygies, 

 so that they are still impossible to distinguish morphologically from the syzygies. 

 Synarthries changed in this way are called pseudo-syzygies by Clark. 



In order to demonstrate the ramification of the arms in my specimens of C. 

 typica I give below a scheme of the ramification in the large specimen. The arran- 

 gement is the Minckert one, which I have modernized and modified. 



Roman numerals signify the number of the division series, thus for instance 

 II = II Br, arabic ones = the ordinals of the segments. Br as usual = Brachial. R = 

 Radiale; Rj in this case (counted from the dorsal side) is situated sideways, left of 

 the mouth, then follow R 2) R ;j etc, in the direction of the pointer. Syzygies and 

 synarthries certainly have different marks, but they pass över to each other to an 

 unlimited extent, so that instead of a mark I have often put a query. Where the 

 » pseudo-S3 r z3 T gy » is fully developed I have denoted it by the same symbol as a 

 'true» syzygy. 



The regenerate I have marked by enclosing an index to the number of the 



