4 Richard Hftgg. 



with oblong, light spots which have a narrow margin of a blackish 

 brown colour and a very small black point in the centre. 



Hab. Tor on the Red Sea. 



The species in question belongs to the subdivision Aclesia 

 Rang., in which are included Notarchus savignanus Audouin from 

 the Egyptian shore of the Red Sea and from Natal, N. laciniatus 

 Rupp. et Leuck. from Tor on the Red Sea, N. glaucus Cheeseman, 

 from New Zealand, N. areola Pease from the Sandwich Islands, 

 N. laeinulatus Couthouy from Rio de Janeiro, and N. Pleii Rang. 

 from Rio de Janeiro, the Antilles and West Florida. The nearest 

 relative of this species seems to be N. savignanus. There are also 

 certain agreements between our species and N. laciniatus and 

 laeinulatus. From N. savignanus it is distinguished by the follo- 

 wing qualities: 1) The anterior tentacles are fixed not only by the 

 median border but also by the interior part of the front border. 

 In N. savignanus they are only fixed by the median border. 

 2) The posterior edge of the anterior tentacles is convex, in N. 

 savignanus it is concave. 3) The branchial orifice is situated at 

 the same distance from the front as from the hind end of the 

 body. In N. savignanus it is situated nearer to the front end. 

 4) The branchial orifice is situated somewhat to the right. In 

 N. savignanus it is situated in the middle of the body. 5) The 

 transversal plicature on the front end of the foot has got con- 

 siderably deeper and more numerous indentations on both borders. 

 6) The edge of the foot is supplied, all round, with numerous, 

 apparent, plicated indentations. These are wanting in N. savig- 

 nanus. 7) The foot is not divided into two different sections, as is 

 the case with N. savignanus, but it is homomorphous all through. 



8) The head is not distinctly marked from the body. In N. savig- 

 nanus there is a distinct difference between head and body. 



9) The back part of the body is hardly distinguishable from 

 the middle part. In N. savignanus the limit is very clear. 10) The 

 hind part of the body is not extended into a long point. 11) The 

 processes on the back part of the body are quite different, as 

 far as their place and structure are concerned. Instead of the 

 processes, mentioned above, there are, in N. savignanus, 4 large 

 fingerlike processes on the central part, arranged longitudinally. 

 Besides N. savignanus has on each side two very strong, large, 



