Mr. AV. Thompson on two new species of Nudibranchs. 49 



tiou is very pleasing to me, believing, as I do, that all the species 

 described by Montagu still exist. On a former occasion I was for- 

 tunate enough to obtain his Thccacera penniyera. 



The species described in this paper I was anxious should not rest 

 on my sole authority ; added to which, I was not sufficiently versed 

 in their anatomy to give an equally full description with those in the 

 valuable work on the Nudibranchs i)ublished by the Ray Society. 

 After I had taken my notes, I accordingly despatched them to 

 Messrs. Alder and Hancock, who have kindly placed their descri})- 

 tions at my disposal, and, in the interest of zoological science, I use 

 their descriptions in preference to my own. 



EoLis Adelaid.e. 



" J3ody nearly half an inch long, slender, tapering to a fine point 

 behind, pellucid orange-red. Dorsal tentacles moderately long, 

 smooth, tapering, divergent, and set a little apart at the base ; orange- 

 red with yellow tips, and a pale line down the back of each, termi- 

 nating in a clear oval spot on each side behind the tentacles, on 

 which the minute eyes are placed. Oral tentacles a little shorter than 

 the dorsal pair, and of the same colour, the pale line on their sur- 

 face also extending backward to the clear spot. Branchiae elliptical, 

 inflated, of the same colour as the body, a little deeper towards the 

 top, apices white ; the central gland is yellowish, rather wide, and 

 irregularly foUiculated or lobated ; they are arranged in twelve or 

 thirteen rather distant transverse rows of three or four papilke each, 

 commencing a little behind the tentacles, and divided by a narrow 

 space down the back ; the papilke nearest the dorsal ridge are the 

 largest and the most inflated. Foot pellucid, slightly tinged with 

 orange-red, linear, narrow, tapering gradually to a point a little 

 beyond the branchiae behind, truncated in front, with the angles 

 rounded off. 



"This species most nearly approaches EolisFarranni, Aid. & Han., 

 from which it differs in colour, and in the number and form of its 

 papilke, which are broader towards the apex. The spawn also dif- 

 fers, forming a narrower coil, with the free margin luidulated." 



Ilnb. I obtained two sj)ccimens by dredging in six fathoms water 

 in Weymouth Hay ; the first, which was white in colour, 1 obtained 

 in September 1H5-1, and the second si)ecimen was obtained in the 

 following month. The colour of the last was orange-red ; and this 

 is described by Messrs. Alder and Hancock as the typical example. 

 In each case the Eolis was feeding on Plumularia. The difierence 

 in the colour here shown is a further evidence of the puerility of 

 considering mere colour as a test of species in the lower animals. I 

 have named this lovely Nudibranch in memory of a little daughter, 

 whose love for zoology, and retentive memory on the subject, pro- 

 mised much. 



Eolis c.krumca, Mont. sp. 



Boris ccendeu, Mont. Liim. Trans, vii. 78. pi. 7. f. 4, h. 



" Bodv half an inch long, slender, nearly linear, tapering to a fine 

 point behind, of a pale pellucid green. Head small, very short, and 



Ann. ^ Mag. N. Hist. Scr. 3. J^oL v. 4 



