The Crinoids from Dr. S. Bock's Kxprpition to Japan 1014. 153 



mis nobilis with varieties ami M. luirians Doderlein lias (iislinmiisluni 

 according to the below combined scheme: 



I Large species. Diameter of the stem .") — 7,' mm. i\' Brachials 

 ordiiiai'V. Internodals smootli. without distinct fwrritws between tiic joints. 



M. Hobilis 



[) S intenioda! jdinfs. t'ii'ri extending over 4 internodes. 

 Diameter of the stem 5 — 6 nnn. .") »Kadials» M. nob. ni)-. sumatranus 



2) !) — 10 internodal joints. Cirri extending o\ei" :{ — 4 internodes. 

 Diameter of the stem (i — 7... mm. (>( — 7) »Radials» M. nob. car. limoriensis 



8) 10 — 12 iiiteniixlal jdiiits, Cii-ii extending over 3 internodes. 

 Diameter of the stem (3 — 7 mn). 5 »Kadials» M. nob. var. nobilis. 



4) 18 — 15 Internodal joints, otherwise as in the preceding va- 

 riety. Here is to be mentioned also tiic sp. from Siboga Stat 251, 

 253, 254. ]\I. voh. var. mnrrayi. 



II Small species. Diametei- of tlie stem 4 — 5 nun. K'nrrly 1\ 

 Br-s. Internodal joints 6 — S, Distinct furrows between tlic inteniodals. 

 Cirri extending over 4—5 internodes. M. variant. 



To which species ought the above-described specimens then to 

 be referred? Fi'om the point of view of the diameter of the stem and 

 the number of ]iinini]ai-s they are most closely related to M. varians^ but 

 by the number of internodals, L of cirri and number of eirrals, by the 

 occurrence of IV Br-s, by the number of intei'nodcs with interarticular 

 pores they approach M. nobilis and especially the varieties nobilis and 

 murrayi of this species. Why have I not referi'cd them to these two 

 varieties, which moreover may scarcely be considered as more than 

 types of individual variation? The smallei- diameter of the stem in 

 my specimens is an impoi'tant distinguishing mark, but merely l)ecause 

 of this 1 \\oul(l not establish a new \-ariety, as tiic difference might 

 be due to a difference in age. As I iu^ve jjointed out abo\e, the number 

 of the cii'rals is to a certain degree in proportion to the size of the 

 animal. When therefore, in spile of the delicate stem, the Bockiaii 

 specimens have a number of eirrals reaching or exceeding that stated 

 for M. nobilis. the diffei'ent diameters of the stems cannot be consi- 

 dered as due to differences of age. Besides, the [)roximal pimiules in 

 the new variety are shorter than both in M. nobilis and varians. 



Two of the previously described varieties of M. nobilis show in 

 separate characteristics an approach to M. varians: M. n. var. suma- 



Nova Acta Reg. Soc. Sc. Ups.. Ser. 4. Vol. 6. N:o G. Iiiipr. ' . 1922. 20 



