270 K. MITSUKURI : STUDIES ON 



masses ; small and thinly scattered rings supporting a crown of 

 three to four straight, outwardly directed, rods; and very thinly 

 dispersed star-like deposits, consisting of about five spoon-like rods, 

 with the enlarged perforated ends overlapping one another, and a long 

 straight outwardly directed central rod, the top of which is provided 

 with two curved arms thus bearing some resemblance to the 

 anchors in Sijnapta. Colour in alcohol dirty grey and yellowish- 

 brown. Length 100 to 110 mm." (Theel p. 40). 



Remarks : — The species of Ankyroderma are very difficult to 

 identify. As to A. simile, there are some discrepancies between 

 the description of v. Maoenzeller and that of Thiœl. My specimens 

 may be said to agree with the descriptions in the essential 

 points of structure, and as they came from the same sea — 

 both the " Challenger " and v. Maeenzeller's specimens coming from 

 the Sagami Bay — I have very little doubt in my own mind 

 that they belong to the same species. What lias made the 

 identification very difficult is the fact that the older individuals 

 differ considerably from the young, both in color and calcareous 

 deposits. 



Of my specimens enumerated above, No. 166G is in my 

 opinion a very young individual, while No. 1129 is an older 

 individual, and No. 16 Go the oldest of the three. The difTerences 

 in external appearance are striking. In No. 1 665 the measurements 

 are as follows : body exclusive of tail 4.4 cm.; tail 0.6 cm. ; total 

 length 5.0 cm.; diameter of body 1.7 cm. In No. 1129, length of 

 entire body (tail not apparent) 3.5 cm. ; diameter 2 cm. In No. 

 1666, body exclusive of tail 1.0 cm. long.; tail 0.5 cm. long.; total 

 length 1.5 cm. ; diameter 0.8 cm. The oldest individual has a thick, 

 much wrinkled skin and is dull-red in color. No. 1129 has also 

 a, wrinkled but thinner skin, and is ashen-grey in color. The 



