554 GASTROPODA. [Opiathobranchia. 



Subsp. granulosa, Bergh, 1900. 

 Zool. Jahrb. Syst,, xiii, 1900, 209. 



Colour of dorsal surface dirty-brown, lightly marbled with black, 

 as is also the upper side of the foot ; the gill is brownish-grey, the 

 foot yellowish-white. Back thickly covered with small oval or roundish 

 granules of 0-5-1 mm. diameter, and the same granulations are present 

 on the upper side of the foot and the anterior margin of the veil. The 

 auriform tentacles with a strong furrow on the under-side. Gill with 

 about 30 leaflets on each side. Gland at the posterior end of sole 

 not distinct, pear-shaped, 3-5 mm. long. There is no papilla on the 

 tail. Jaws and radula as in the type. 



Length, 2-5 cm. ; breadth, 1-5 cm. ; height, 1 cm. Breadth of veil, 

 12 mm. ; height of rhinophores, 2-5 mm. : length of gill, 5-5 mm. ; 

 breadth, 3-2 mm. 



Type in the Naturhist. Museum, Bremen. 



Hob. French Pass, type (Schauinsland) ; Te Onepoto, near Lyttel- 

 ton (H. S.). 



SUBORDER 2. NUDIBRANCHIA, Cuvier. 



Naked Opisthobranchs without a shell in the adult state ; without 

 ctenidiuni and osphradium. These animals are generally slug-like 

 and exhibit an external symmetry. The visceral mass, except in the 

 Hedylidce, is no longer a sac marked of? from the foot, and the dorsal 

 integuments frequently give rise to appendages which are subservient 

 to respiration. The nervous system is much concentrated ; the 

 ganglia are generally united on the dorsal side of the oesophagus ; the 

 supra-intestinal and infra-intestinal ganglia are fused with the pleurals ; 

 the fusion is sometimes carried to a great extent, but the several infra- 

 oesophagal commissures (pedal, visceral, and stomato-gastric) always 

 remain distinct. The visceral commissure is always reduced, and is 

 generally without a ganglion. Accessory stomato-gastric or " gastro- 

 oesophageal ' ! ganglia are present. The genital gland or gonad is 

 subdivided into male and female acini, except in the Elysiomorpha. 



The Nudibranchia are marine, generally carnivorous, and brightly 

 coloured, affording many instances of mimicry. There is no os- 

 phradium, but its absence is compensated by the increased develop- 

 ment of the olfactory organ, or rhinophore. In ontogeny the free 

 veliger stage of Nudibranchs is followed by a planariform creeping 

 stage, during which the shell is rapidly lost ; and finally the dorsal 

 appendages are acquired, notably the dorsal papilla* of the Eolids. of 

 which the most anterior are first to be developed. 



Tribe 1. TRITONIOMOEPHA. 



Nudibranchia in which the liver is wholly or partially contained 

 in the visceral mass. The anus is lateral, on the right side. There are 

 generally 2 rows of ramified dorsal appendages. The genital duct is 

 diaulic ; the male and female orifices contiguous. 



