Fam. 1, Plates 1 and 2. 



Genus 1. DORIS,* Linn^us. 



Co?'pus ellipticum, depressum, rarius convexum, pallio plerumque tuberculato obtectum; pallium 

 ultra caput et pedem extensum. Caput inferius, tentaculis 2 labialibus, nonnunquam obsoletis, vel in 

 velum conjunctis. Tentacula dorsalia 2, subclavata et laminata, intra foramina retractilia. Branchiae 

 plumose, anum circumdantes, postice in linea media dorsi positse. Apertura genitalis ad latus 

 dextrum. 



When Linnaeus first proposed the genus Boris, in the tenth edition of the ' Systema 

 Naturae,' he so far misunderstood its characters as to describe the vent for the mouth, which 

 he conceived to be surrounded by a circle of tentacles. This mistake, pardonable in that 

 early stage of science, he corrected in the twelfth edition of his celebrated work, and the 

 genus, as there described, and for the first time properly established, is pretty nearly the 

 same as it is now understood by zoologists of the present day. Gmelin, however, so much 

 enlarged the limits of the genus Doris as to make it nearly co-extensive with the whole order 

 of the Nudibranchiate Mollusca, and his example was followed by most of the naturalists of 

 the Linnsean School. In the more accurate classification of Cuvier, Doris was again reduced 

 within the limits of the Linnaean characters, though from the imperfect knowledge of these 

 animals still at that time prevailing, many species were at first included in it, which were 

 afterwards detached to form new genera, as these characters became better understood. It is 

 not necessary to enumerate the genera that were thus formed, as most of them will be found 

 described in the family of the Dorididce. Even as at present restricted, the genus still 

 contains a large number of species, and that number is daily being increased by the discoveries 

 of modern travellers, as well as by the more careful investigation of native species by 

 European zoologists. As yet the different groups are scarcely sufficiently understood to allow 

 of a satisfactory division of the whole genus ; but at some not very distant period, such a 

 division will certainly be required, and distinctive characters are not wanting on which 

 several new genera might be established. Before noticing some of the attempts that have 

 been made towards the accomplishment of this object, it will be necessary to give a more 

 detailed view of the characters of the genus as it at present stands. 



The body of Boris is elliptical, and generally more or less depressed, but in some species 

 convex. It is covered on all sides by a cloak, which extends beyond the head and foot ; the 

 cloak is generally tuberculated or granulated, seldom quite smooth, and is more or less 

 stiffened with calcareous spicula, imbedded in its substance. The head is indistinct, placed 



* Doris, a sea-nymph, daughter of Oceanus and Thetys. 



