MOLLUSCA. 783 



sound which this little animal produces under water, GRANT Ann. des Sc. 

 not. viii. pp. in, 112, and S. KEID Ann. of Nat. Hist. xvn. p. 389. 



b) With branchice disposed in a continuous series; with cup of tentacles 

 entire. 



Tritonia ALD. and HANG. 



Sp. Tritonia Homlergii Cuv. Ann. du Mus. I. pp. 418 498, PL 31, 32, Moll., 

 Mem. 4 ; BLAINV. PI. 46, figs. 6, &c. 



Polycera Cuv. Body attenuate posteriorly with belly flat, 

 covered by a loose membrane. Dorsal branchiae in little branches 

 or plumose, covered with membranous laminae or papillae. Veil of 

 head running out anteriorly into several cirri or tentaculiform 

 laciniae. Two clavate tentacles. 



JEgirus LOVEN. Tentacles vaginate, simple. 



Sp. Polycera punctilucens D'ORBIGNY, GUERIN Magasin de Zool. 1837, 

 Mollusq. p. 1 06. 



Polycera LOVEN. Tentacles naked, annulate with transverse 

 lamellae. 



Sp. Polycera cornuta, Doris cornuta ABILDGAARD, Zool. Danica, Tab. 145, 

 figs, i 3, BLAINV. Malac. PL 46, fig. 10 ; according to LOVN Doris quad- 

 rilineata MUELL. Zool. Dan. Tab. 17, figs. 4 6, Tab. 138, figs. 5, 6, and 

 Polycera ornata D'OfiB., GUERIN Mag. L 1. PL 107, ought to be brought 

 under the same species. Comp. on this genus ALDER Annals of Nat. 

 Hist. vi. 1841, pp. 337 342, PL ix., FREY u. LEUCKART Beitr. zwr 

 Kenntniss wirbell. Thiere, a. 66 70. 



TetJiys L. Body somewhat oblong, depressed, furnished ante- 

 riorly with a broad funnel-shaped, fimbriated veil, behind the veil 

 contracted into a species of neck. Mouth proboscidious, retractile, 

 in the bottom of velum. Two conical tentacles at the base of 

 velum, margined by a broad cup-shaped sheath. Apertures of 

 generation and vent at the right side, in the anterior part of body. 

 Two rows of branchiae at the sides of back; cirrose pectinate 

 branchiae alternating with smaller bundles. 



Sp. Tethys leporina L., RONDELET Pise. p. 526, tertia leporis marini Species, 

 Cuv. Ann. du Mus. xn. pp. 259 270, PL 24, Me"m. sur les Moll, vn., 

 BLAINV. Malacol. PL 46 bis, fig. 9 ; in the Mediterranean ; the Teth. ftm- 

 bria L., BOHADSCH De quibusd. Anim. marin., Tab. v. figs, i, 2, appears 

 not to differ from it. DELLE CHIAJE adopts two species, as does LINNAEUS, 

 Memorie, in. p. 138, but his Teth. fimbria is not that of LINN^US, which is 

 distinguished by the absence of filaments at the margin of the velum. 



Triopa JOHNST. (species of Tritonia Cuv., species of Euploca- 

 mus PHIL.). 



