ELIOT — NUDIBRANOHS. 427 



14 Flatydoris tabulata (Abraham). 



P. S. Abraham, Revisioa of the Anthobranchiate Nudibr. MoUuspa, Proc. Zool. Soc. 1877 

 p. 249. 



One specimen, without notes as to locality. It is small compared with those in other 

 collections, and perhaps not full-grown. Length 43 mm., breadth 29. Foot only 

 26 mm. long and 5-7 mm. wide. Mantle-margin very ample : 10-12 mm. wide. The 

 whole animal is very flat and hard, and the back is covered with numerous very minute 

 papillae. The ground-colour of both the upper and lower surface is yellowish white. 

 Much of the dorsal area is covered with fine purple dots, but there are considerable 

 bare spaces in the middle and elsewhere. The absence of dots on them may, however, 

 be due to abrasion. On the underside of the mantle is a band of purple dots round the 

 foot. The rhinophores are dark violet-grey. The branchiae are six and tripinnate : 

 their main axes are reddish below ; the prefoliations are violet-grey ; in all parts there 

 are numerous dark dots. The pocket is indistinctly six-toothed. The oral tentacles 

 are large and grooved. 



The labial cuticle bears an armature of rods, which though of a faint grey and not 

 conspicuous is yet distinct. It consists of two longish plates, which are thicker and 

 darker at the ends where they are nearest each other. The maximum formula of the 

 radula is 30x80.0.80. The outermost tooth has no hook, but bears irregular 

 denticles on the apex and also occasionally on the side. The outermost tooth but one 

 bears a hook which is reduced but still clear, and below it a few irregular denticles. 

 The remaining teeth are hamate and rather slender. 



The oesophagus is rather large. The stomach lies in a cleft of the liver, but is not 

 enclosed by it. Its walls are thin, not muscular, and slightly laminated internally. 

 The liver is brown and traversed internally by unusually large tubes and passages. 

 It is covered by a thick yellowish layer composed of the hermaphrodite gland. 



The blood-gland is purplish grey and composed of two parts, of which the anterior is 

 larger. The ganglia of the central nervous system are yellowish and fairly distinct. 

 The common commissure is very distinct. The eyes are set on short stalks. 



The ampulla of the hermaphrodite gland forms two or three thick convolutions. The 

 albumen and mucus glands are of moderate size. The spermatotheca is round, brown, 

 and full of spermatozoa. The spermatocyst is elongate and stalked ; it rises close to the 

 spermatotheca and is bent on itself, so as to appear double. The prostate is large and 

 globular. Attached to the bag which contains the penis is a pear-shaped flocculent 

 gland with a longish duet. The lower part of the vas deferens (and it would appear the 

 glans penis too) bears strong, jagged, pinkish folds, which rise into bent spines of a 

 pinkish colour set in six rows. Higher up there are no spines but only jagged 

 colourless folds. The vagina is lined with a thick red cuticle bearing folds on which are 

 knobs and prominences. Though the whole armature is very similar to that of the male 

 branch, there are no true spines in it. 



This form is nearly allied to Bergh's PI. variegata, which also possesses the anomalous 

 character of a labial armature and a somewhat similar radula. The two may be varieties 



SECOND SERIES. — ZOOLOGY, VOL. XIII. 57 



