187 



were not very good, Ihe embryos developiiii* only to the beginning forma- 

 tion of the I^ipinnaria; the somewhat unexpected fact that this species 

 has a typical judagic larva was, however, already proved by this first 

 attempt. On Ihe l<Slh of June I had the pleasure of seeing a female spec- 

 imen, kepi in a dish together with a number of other specimens, discharge 

 its eggs, from which an excellent culture was obtained. I regret not having 

 noticed the exact size of the eggs, only slating that Ihey are small; I think 



I remember thai Ihey were of yellowish colour. The cleavage began very 

 soon after the fertilization ; the fact thai I have made no notices about 

 the cleavage process mosl likely indicates I ha I il is of the usual, regular 

 type. After 16 hours the gastrula stage was reached, and at the age of 

 two days the embryos had the typical Bipinnaria-shape. The larva? were 

 generally found swimming close to the bottom of Ihe dish. At the age of 

 10 days the enterocoel pouches had united in the anterior end of the body. 

 At the age of 18 days some few of the larvae were in the metamorphosis- 

 stage and, accordingly, had reached the full larval shape. 



The young larva (PI. XXXI II, Fig. 1) looks very much like the Aslro- 

 peden-larxa, with small, non-contractile processes; there are no postoral 

 or preoral processes. The suboral cavity is small, not very deep. It is espec- 

 ially noticeable that the vibratile band of the ventral median process is 

 as distinctly developed as the rest of the bands, contrary to what is gener- 

 ally the case in larvae having a Brachiolaria-stage. It was, therefore, a 

 great surprise to me to see that this larva in its final stage really is a 

 Brachiolaria (PI. XXXllI, Fig. 2), though of another type than the Bra- 

 chiolaria of Aslcrias. At each side of the fairly large sucking disk there 

 is a small brachiolarian process with a few papilla^ at the end. I was un- 

 able to ascertain the exact number of these papillae, as also to ascertain 

 whether the vibratile band continues along the paired brachiolarian pro- 

 cesses. The median process is only slightly transformed, retaining its flat 

 shape, and its vibratile band bordering it as in the younger stage; only 

 a row of small papilla', 3-5 in number, along each side, inside the band, 

 indicates its brachiolarian character. The other processes remain unaltered, 

 short and small. The length of the fully formed larva is ca. 0,6 — 7 mm. 



II is unpigmented. 



Asterina (Patiriella) regularis \ errlll. 



Among a large number of specimens of this species which 1 collected 

 on the rocky shore at the Island Bay, outside Wellington, New Zealand, 

 on the 17th of February 1915 1 found a few specimens to contain partly 

 ripe sexual products. The artificial fertilization which 1 undertook was not 



24* 



