I0I4. CoLOAN. — Opisthohranch Fauna of Co. Dublin. 177 
Actaeonias when they left the egg differed from the adult 
in little more than size and the absence of tentacles. This 
striking peculiarity, the absence of any larval metamor- 
phosis in the development of A. Cocksi was pointed out 
by Pelseneer in his paper La Condensation cmhryogeniquc 
chcz un Nudihranchc in which the embryology of the species 
is lucidlv described and figured.^ 
Sub-Order — xudibranxiiiata. 
Aeolis papulosa (Linne). 
Not infrequent living under stones about low-water 
mark ; occasional in dredgings. " Three individuals were 
found by Dr. Lloyd at Malahide ; also found by myself at 
Lambay Island " : Thompson '40A. Fifteen specimens 
taken in 10 gatherings at Lambay, at Rush, at Skerries, 
and at Bullock, 1906-14 ; i dredged in 10 f. at Bullock, 
1906, and another in 14 f. off Howth Head, 1907 : N .C. 
Largest, 62 mm. long. 
This species, as is probablv the case with many others 
of the Aeolidian nudibranchs, travels by floating with the 
tide, as well as by crawling. At Rush in May, 1906, I saw 
a large individual drifting in rapidly with the tide, half 
floating and half swimming with a wriggling motion 
of the body. The number of embryos in the egg varies 
considerably. Alder and Hancock (Monograph) give tlie 
number as 2 or 3. Pelseneer [Emhryologie des Gastropodcs-) 
says there are normally 3 or 4, that sometimes 5, 6, 7 or 8 
are found, and that once he observed 12 in a single egg. 
On fhe Dublin coast 3 appears to be the normal number ; 
but in a coil taken at Skerries in 1913, I found the number 
to vary from 3 to 7 in each egg, the usual number being 6. 
In three individuals, respectively, 25, 50, and 65 mm. 
long when in motion, the number of teeth in the radula 
J Travanx de la Station Zoologique de Wimeretix, vii. pp. 513-5201, 
1899- 
^Menioires de I'Academie Roy. de Bel^ique. Ser. 2. Tome iii., 191 1. 
