1906.] «F SOUTHERN INDIA AND CEYLON. 659 



excrescences, from which spicules project here and there. But 

 in all three specimens there are sevei-al bald spaces on either 

 side, not connected, but arranged in a more or less continuous 

 line from the rhinophores to the branchial pocket. The integu- 

 ments are stiif, but not harsh to the touch. They are full of 

 rod-like spicules, straight or slightly curved but not branched, 

 set in an irregular stellate pattern which is not conspicuous. 

 They form columns under the tubercles. The rhinophores are 

 dark grey. The pockets open in hillocks covered with tubercles 

 like the rest of the back, but not protected by special valves. 

 The branchiae are also grey, five or six in number and mostly 

 bip innate, but tripinnate in places. The margin of the pocket is 

 hardly raised, undulated, but not stellate and not protected by 

 tubercles. The mantle-margin is fairly wide. The anterior 

 m.argin of the foot has a shallow groove and a rather distinct 

 notch in the middle. The oral tentacles are white, digitate, and 

 tapering ; small, but quite distinct. 



The blood-gland is flocculent and pinkish. The central nervous 

 system is enclosed in a strong capsule and is granulate. The 

 ganglia touch one another. The pedal ganglia are i-ound ; the 

 cerebro-pleural are separated into two divisions with moderate 

 distinctness. Under the oesophagus passes the strong, broad, 

 short, common commissure. Mr. Farran found both salivary and 

 ptyaline glands on the buccal mass, and I also found at least two 

 sets of glandular organs. Two glands open into the oesophagus 

 close to the central nervous system ; they are band-like and 

 granulate, with long thin ducts. Two other glands, apparently 

 connected with the buccal mass, are large, white, opaque, flocculent, 

 but compact. I could not discover where they open. Close to 

 the mouth I found a gland-like bladder containing irregularly- 

 shaped spicules. JSTo labial armature was found. 



The yellow radula consists of 38 rows, two of which are un- 

 developed and shadowy. The lateral teeth are 39, as in 

 Mr. Farran's specimen, and the number seems remarkably con- 

 stant. The 1 innermost are smaller than the rest, rather straight, 

 and bear a single minute denticle, sometimes connected with a 

 ridge, on the outer side. In the middle of the half row the teeth 

 are larger and more distinctly hamate. The two or three outer- 

 most are small and bear hair-like denticles. 



The stomach is rather large and not enclosed in the liver; 

 under it lies a rather large, white, pear-shaped gall-bladder. The 

 liver is greenish internally ; externally it is covered by a thick 

 white layer of the hermaphrodite gland. The genitalia are 

 unarmed. Both the spermatothecas are pinkish and globular, but 

 one is three times as large as the other. 



Generically this form seems to me referable to Trippa rather 

 than to Thordisa. Both Mr. Farran and myself found ptyahne 

 glands, which are regarded as characteristic of the genus. The 

 back is covered with prominences which are often compound. 

 The bald patches perhaps correspond to the pits found in other 



