162 T. GisLÉN, 



In 1884 P. n. Carpenter in the Challenger Kxp. mentioned the 

 80 called Vega-specimen as a separate species (in tiic talilc p. 344), and 

 then the following year (Trans. Linn. Soc.) he discussed its separate 

 position. According to him the species in quoslion had higher internodal 

 joints (both relatively and absolutely), wiiicli was of less diameter than 

 in M. interniptus and regularly radiais, that is according to a more 

 modern indication I Br 7 (1 + 2, 4+5). In the collections of the Upp- 

 sala museum there is also a specimen of a Metacrimis taken by the 

 Vega-expedition in the Yedo-Bay at a depth of 05 fath. Witli regard 

 to the diameter of the stem it approaches most to M. rolundus (the 

 diameter is 0,o — 5,8 mm.) The internodal joints are really somewhat 

 higher (1,4 — 1,5:. mm.) than in M. rolundus, where, according to my 

 calculations, the h of the segments is 1,3 — 1,4 mm. (The last described 

 specimen 7 differs by the segment being only l,i:. — 1,3.-. mm.)'. Neverthe- 

 less it does not seem advisable to distinguish the Vega-Specimen even 

 as a variety on the basis of such vague features. (Observe that the 

 original Vega-specimen is said to have a slender stem. If it is a 

 young specimen of M. rotundus it is perfectly natural that the joints 

 are rather high, at least relatively.) As to the »Radiais» they are in 

 the Vega-specimen at my disposal: 6 :4 cases, 7 : 1 case (according to 

 Carpenter's indication) or I Br 5 : 1 case, 6 (3 + 4) 3 cases, 7 (3 + 4) 

 1 : case (modern indication). II Br-s are in the case at hand 7 (3 + 4) 

 3 cases, 9 (3 + 4 or 4 + 5) 2 cases, 11 (3 + 4 or 2 + 3) 2 cases, the 

 other ones broken. Thus it differs in no essential way from M. 

 rohmdns, to which species I therefore refer the »Vega-specimen» of 

 P. H. Carpenter. 



In the same work as he described M. rotundus P. H. Carpenter 

 gives an account of the appearance of a stem-fragment of a Metacri- 

 nus from Singapore, which he calls M. Steioarti. This species is said 

 to be distinguished from M. rotundus and interruptus (which it approaches 

 most closely) by the statement that, »the joints have much more 

 distinct horizontal ridges (p. 443). They give it a certain amount of 

 resemblance to the stems of M. Wyvilli and cingulatus». The separate 

 position of the species is evidently considered by the author to be most 

 clearly demonstrated by the different appearance of the infranodal 



* The h of the joints is obtained by measuring the whole internode and dividing 

 its L by the number ol' internodal joints. 



