KOTICE OF EMBLETONIA PALLIDA. 153 



St. Ethchidce), tlistingnisbecl from Clavula Gossii (Di*. 

 Wright) by tlie sub-uniserial position of tlie tentacles, and 

 by its greater size and robustness, (fig. 2, a and h.) 



Feeding on these I fouud uumerous specimens of the 

 Singular mollusk of wbich 1 belleve tbat I now give the 

 first publlshed figure — Embhtonia hyalina^ (fig. 1.) It was 

 originally discovered by Mr. Price on the present sIte of 

 the Birkenhead docks, in 1854; biit -vvhen the docks were 

 finished, the sIte was destroyed, and the animal has not 

 been since met Avith. 



It feeds principally on Laodomea gelatinosa, neglecting 

 other zoophytes while any of that remains. It lays its eggs 

 in small reniform masses, with but few eggs in each mass. 

 It appears to be hardy in confinement, some of the speci- 

 mens having llved eight or ten weeks in jars of sea water, 

 but they are sluggish in their movements, and were 

 generally to be found on the same stone for days together. 

 It is distinguished from the other British species of the 

 genus by the double row of papHke on each side, and also 

 by the colour, whicli in E. pulchra and minuta is red, 

 whereas in this animal it is of so light a blue that it 

 only gives a slight opacity to the aniaial, the tentacles 

 alone being of a pale yellow ; and also by the form of the 

 lobes of the head, which are in this species united into a 

 semicircular veil, but in pulchra and minuta they form a 

 crescent with blunt horns pointing rather forwards. 



Casual observers might mistake Eolis (Tergipes) exigua 

 or despecta for this animal, but both of these have four 

 tentacles instead of two, and the colouring, although some- 

 what similar, is very different on close examination. 



In the same pools I found an Infusorium, different from 

 any I have been able to obtain a description of. I give a 

 slight sketch of it (fig. 3), in order that if recognised by 



VOL. X., 1860, PAßT II. V 



