1878.] THE MARQUIS OF TWEEDDALE ON A NEW HORNBILL. 277 



3. Aclesia glauca, n. sp. (Plate XV. fig. 4.) 



Body from 3 to 5 inches long, about ovate when at rest, but 

 capable of considerable extension, a little contracted behind the 

 head, then elevated, and suddenly sloping to a point posteriorly ; 

 entirely covered with numerous simple and branched tentacle-like 

 processes, the largest of which are sometimes eight lines long. 

 Colour on the sides pale greyish-brown, passing on the back into a 

 dull sea-green ; the whole surface with numerous irregularly shaped 

 black blotches that are longest on the back. Along the back there 

 is also a double row of from 8 to 1 2 emerald-green specks, each sur- 

 rounded with a zone of umber. Dorsal tentacles f inch long, folded 

 down the outer side so as to appear tubular, beset with filiform ap- 

 pendages. Labial tentacles similar in shape, but rather larger. 

 Branchial cavity large, protected by the folded-in edges of the 

 mantle, branchiae quite internal ; foot long and narrow, pointed be- 

 hind, without side-lobes as in Aplysia, sole pale sea-green ; mouth 

 roundish, placed under the head ; odontophore with very numerous 

 rows of simple hooked teeth ; gizzard strengthened with large trian- 

 gular calcareous plates ; shell none. 



Like many of the species of the allied genus Aplysia, this animal 

 possesses the power of emitting a purple fluid from the edges of the 

 mantle, but only in small quantity ; and it may often be handled 

 without any thing of the kind being observed. All my specimens 

 are from Auckland Harbour, and were obtained from rather sandy 

 localities near the extreme verge of low-water mark. 



EXPLANATION OF PLATE XV. 



Fig. 1. Pleurobranchm ornatus. 



2. Shell of the same. 



3. Pleurobranckcea ncvce-sealandim. 



4. Aclesia glauca. 



8. On a new Species of the Genus Buceros. By Arthur, 

 Marquis of Tweeddale, F.R.S., President of the Society. 



[Received February 2, 1878.] 



In a collection of birds made at Amparo (in the extreme south of 

 the Philippine island of Leyte), and sent to me by Mr. Everett, 

 are some examples of a Hornbill of the genus Buceros, which differ 

 from the two other known Philippine species ' sufficiently to require 

 description. The characters which differentiate the large Buceros 

 of Mindanao, B. mindanensis, from the one which inhabits Luzon 

 were stated some months ago before this Society (see P. Z. S. 1877, 

 543). But in those two species the form and general contour of 

 the bill and casque are alike, whereas in this second representative 

 form of B. hydrocorax the form of the casque is very different. 

 The colouring of the bill resembles that of B. mindanensis ; and in 

 1 B. hydrocorax and B. mindanensis. 



