OXYNOEID. 161 
The genus Symprerus Rafinesque, Analyse de la Nature, ou 
Tabl. de Univers et des Corps Organises, 1815, p. 142, is placed by 
Rafinesque between Laplysia and Dolabella. It is an absolutely 
nude name. 
Genus Norarcuus (page 135). 
APLYSsIA SALTATOR Forbes. A. corpore globoso, griseo albo 
nigroque maculato, tuberculato, tuberculis mucronatis ; sinu branch- 
ali parvo; pede augustissimo, tentacules brevibus. 
Long. 2 une,; Altitude 114. Hab. 20-30 fms. Serpho Bay 
[ZEgean Sea]. (Forbes, in Rep. Brit. Asso. Adv. Sci., 1843, p. 187). 
Family OXYNOEID Fischer. 
Animal elongated, narrow, with rolled tentacles and well-de- 
veloped pleuropodial lobes. Male orifice near the right tentacle ; 
female orifice on the right side at the edge of the mantle cavity ; no 
external groove between the orifices, the vas deferens being internal. 
Gill composed of numerous delicate parallel leaflets, depending from 
the roof of mantle-cavity, not forming a free plume. Radula com- 
posed of a single series of lance-like teeth. Shell Bulliform, ex- 
ternal, involute with concealed spire, thin and fragile, oval, incap- 
able of containing the soft parts. 
The genera composing this group were referred by Pagenstecher 
in 1874 to a new Order which he called Monostichoglossata, inelud- 
eluding Limapontia, Elysia, Lophocercus and Lobiger; the group 
being based mainly on the peculiar radula. Later, Bergh (Malak. 
Untersuch.) forms a group Ascoglossa; and von Ihering, in 1877 
(Vergleich. Anat. Nervensyst, p. 196), names the Order Sacoglossa, 
including Limapontiide, Elysiide, Phyllobranchide, Placobranch- 
ide, Hermeide and Lophocercide. Mazzarelli, in 1892 (Bull. Soc. 
Nat. Napoli, p. 98, and Mem. Soc. Ital. Sci. (8), ix, p. 1), in- 
vestigated the anatomy of Lobiger, tinding the nephridia as in many 
Nudibranchs, nervous system as in Ascoglossa; generative organs 
fundamentally Ascoglossan, but the ovary and testis are separated. 
He concludes that the Oxynoeide represent the most primitive 
Ascoglossa, derived phylogenetically from the more primitive Tecti- 
branchs (Bulloidea) near the point of origin of the Pleurobranchs. 
On the other hand, Oxynoeide differ from the Ascoglossa in hay- 
ing a well-developed shell in the adult, a true gill (although differ- 
ing much from the normal Tectibranch gill), and in the compact 
ila 
