On a New Brachiate Asteroid Larva. 195 
probably not in the former. It will be seen from what follows that this 
conjecture is incorrect. 
The plankton material from the Irish Fisheries Department, referred to 
above, included five! advanced larve of Z. ciliaris, from one of which the 
accompanying figure (Fig. 3) has been drawn to scale. As regards the two 
median lobes or processes, the ventral median one is about three-quarters of 
the length of the dorsal median one, and the latter is very distinctly broadened 
at its extremity and shows a convex or rounded contour in the middle line 
anteriorly. The two lobes are bordered by their respective ciliated bands, 
which have become attenuated almost out of recognition. With reference to 
the ciliated appendages it will be remembered (Mortensen 2/, p. 5) that, 
excluding the dorsal and ventral median processes, there are five ciliated 
processes on each side in the typical asteroid larva, namely, the preoral, the 
anterior dorsal, the posterior dorsal, the postero-lateral, and the post-oral, the 
first named being an extension of the preoral ciliated band and the remainder 
extensions of the post-oral ciliated band. However, it will be seen from Fig. 3 
that in the bipinnaria of Z. ciliaris there are not five but seven ciliated 
appendages in the neighbourhood of the mouth, and that of these 
No. 1 is connected with the preoral band, and corresponds with the 
typical asteroid preoral ciliated process. 
Nos. 2-7 are connected with the post-oral ciliated band, and have the 
following relations :— 
Nos. 2 and 3 arise by a short common stalk nearly opposite to No. 1. 
The corresponding pair in the larva of Z. sasi were considered 
by Mortensen to represent a deeply cleft anterior dorsal process 
(21, p. 38). 
No. 4 arises close behind the stalk just named, and is still well in front 
of the angle of the mouth. The corresponding one in J. sasi was 
termed by Mortensen the middle dorsal process (21, p. 38). 
No. 5 arises behind the angle of the mouth and no doubt represents the 
typical posterior dorsal process. 
1Dava oF ReEcorDs. 
19.8.03. 30 miles W.N.W. of Tearaght Island, S.W. of Ireland, surface. (10, 1903, 
: p. 70, Station 8.R. 51.) One specimen with 11 pairs of sucker feet. 
10.11.03. 50 miles W.N.W. of Tearaght Island, 50 fathoms. (10, 1903, p. 72, Station 
S.R. 65.) One specimen with 9 pairs of sucker feet. 
3.11.05. 10 miles S.W. of Fastnet Rock, S.W. of Ireland, 26 fathoms. (10, 1905, p. 108, 
Station 8.R. 267.) One specimen with 8 pairs of sucker feet. 
11.8.10. 60 miles W.3N. of Tearaght Island. (10, 1910, p. 180, Station S.R. 1001.) 
Two specimens with 12 and 9 pairs of sucker feet respectively. 
