ELIOT— NUDIBRANCHS. 415 



of the row they appear thin and filamentous, possibly because they have become worn 

 or folded on themselves. The radula consists of about twenty-six rows, one or two of 

 wliich are imperfectly developed and shadowy. Math a constant formula of 4 . 1 . 4. The 

 teeth are neatly arranged in a close-fitting mosaic. The base of the large median tooth, 

 which is arched and hollowed out behind, is nearly twice as broad as all the four laterals 

 together. It bears a single cusp, large and only slightly bent downwards. The first 

 lateral is about three-fifths the length of the median tooth, but only a quarter of its 

 breadth, with a single hamate cusp. The second and third laterals are similar but 

 slightly smaller and more bent. The outermost tooth is considerably smaller but more 

 erect and stands up conspicuously at either end of the row. There are two salivary 

 glands ; their distal portions are expanded and spread over the genitalia and stomach. 

 Tlie left is much larger than the right. The remaining portion of each gland is band- 

 lilce and terminates in a long thin duct which passes through the nerve collar and enters 

 the posterior part of the buccal mass. Several glands, probably ptyaline, open into 

 the buccal cavity, but they are embedded in the wall of the cavity and are not visible 

 on its outer surface. 



The oesophagus is not long, and leads straight into the stomach, which is divided into 

 two parts by a constriction more marked on the right than on the left side. There is no 

 structural difference in the walls of these two divisions, and neither contains any spines 

 or plates, but as the hepatic ducts all open into the second division, the first should 

 perhaps be regarded as a dilatation of the oesophagus. Neither contained any solid food 

 in any specimen. The intestine issues from the mid-dorsal surface of the second 

 division and, after describing a broad loop backwards and downwards, runs to the anal 

 opening, which is an inconspicuous papilla on the right side, lying below the mantle 

 edge and just at the point where it joins the body. TJie loop of the intestine bears a 

 single longitudinal ridge resembling the typhlosole found in Lumbi-icus. 



Tlie stomach receives three hepatic ducts : one on the right, close to the exit of the 

 intestine ; one on the left, not quite opposite to it, but a little posterior ; and one behind. 

 The posterior and left ducts bifurcate close to the stomach and then ramify into 

 branches composed of follicles which are not only found in the body cavity but enter 

 the body wall and dorsal integuments, extendiug to within a short distance of the 

 mantle brim. The arrangement and extent of the right duct is essentially the same, but 

 the follicles are developed more luxuriously on this side than on the left, and the 

 bifurcation is less clear, although the duct runs in two directions, backwards and 

 forwards. The right and posterior branches anastomose, but though the right and left 

 branches almost meet anteriorly they seem not to communicate, nor do the posterior and 

 left branches. All three branches consist of variously-shaped follicles communicating 

 with one another, so as to offer a continuous passage but not forming a cylindrical tube 

 except in the main ducts. For some distance from the point of .entry into the stomach 

 the walls of the main duct bear folds which dovetail into one another in the middle of 

 the luraen and form a valve or strainer. 



The cells which line the hepatic lobules are columnar or cubical and highly granular. 

 Some are in a distended condition, others are attached to the wall of the lobule only by 



