Fam. 2, Plate 4. 



TRITONIA LINEATA, Alder and Hancock. 



T. gracilis, alba, pellucida j dorso linea alba opaca utrinque notato ; velo processibus linearibus 4 ; 

 branchiis parvis, pinnatis, utroque dorsi latere 5. 



Tritonia lineata, Aid. and Hanc., in Ann. Nat. Hist., 2d ser., v. 1, p. 191. 

 Hab. Under stones between tide-marks, Scarborough, /. A. 



Body five eighths of an inch long, very slender, linear, pellucid white, with an opaque 

 white line along each side of the back ; sides parallel. Veil rather narrow, produced in front 

 into four long filaments, the two nearest the centre longest. They are pellucid, with opaque 

 tips. Tentacles entire and colourless below, pale yellow above, and divided into several stems, 

 with delicate and slender laminae or branches. The principal stem, situated posteriorly, is 

 thicker and longer than the rest, and truncated at the top. Sheaths rather long and tightish, 

 expanding a little above ; the margins undulating. The eyes are distinctly seen behind the 

 tentacles. The back is very delicately, scarcely perceptibly, tuberculated, and from its 

 transparency shows the viscera through of a pale yellowish or rosy hue. The two opaque 

 white lines unite into a point above the head in front, diverging thence toward the tentacles, 

 and are continued along the sides of the back, curving outwards opposite each pair of 

 branchial tufts ; they unite again posteriorly, and are continued in a central line to the tail. 

 The pallial ridge is somewhat produced. Branchial rather slender, imperfectly bipinnate, 

 transparent, white, with an opaque white line in the centre of each, running into those on 

 the back : there are four or five pairs of branchial tufts, the posterior ones very small. Head 

 scarcely distinct from the veil, the mouth opening inferiorly. Foot slender, rounded in front, 

 and tapering to a point behind ; the liver forming a reddish-yellow patch down the centre. 



We obtained this delicate and graceful little Tritonia, — very distinct from anything 

 before recorded,— under large flat stones among the rocks north of Scarborough, which we 

 explored in September, 1846, in company with our friend Mr. Bean, Two specimens only 

 were found, one by ourselves, and a second by that gentleman. They lived with us for some 

 time, and deposited one or two patches of spawn. The eggs are imbedded in a narrow, 

 transparent belt, rather closely coiled about four times. 



Figs. 1, 2, 3. Tritonia lineata, different views. 



4. A tentacle, more highly magnified 



5. A branchial tuft. 



6. Spawn (the coil is reversed by mistake). 



7. A small portion of the same, showing the eggs. 



