MOLLUSC A. 791 



Sp. Patella vulgata L., BLAINV. Malawi. PL 48, fig. i, PI. 49, fig. i ; Patella 

 granatina L., LISTER Conchyl. Tab. 534, fig. 13; Patella compressa L., 

 LISTER, Tab. 541, fig. 25, BLAINV. PI. 49, fig. 2, &c. 



Appendix to the Cyclobranchiata. 



NematobrancTiia MENEE (Cirrobranchiata BLAINV.). (An ab- 

 normal, aberrant, family.) 



Dentalium L. Shell tubular, elongato-conical, subarcuate, per- 

 vious at both extremities, with posterior aperture narrow, a fissure 

 often extending upon the shell. Animal conical, eyes none, bran- 

 chiae composed of many cirri arranged in two fasciculi. 



The genus Dentalium, placed by LINN.EUS with Patella, and referred by 

 later writers to the ringed worms, belongs in reality, according to the 

 investigations of SAVIGNT and DESHATES, to the Mollusca, although it is 

 difficult to unite that genus with any of the other families. It forms a 

 small group between the Heteropoda and Asplddbranchiata (Emarginula). 

 The species are numerous ; many are extinct, and occur in various tertiary 

 and secondary formations. 



Sp. Dentalium elepTiantinum L., MARTINI Conchyl. Tab. i. fig. 4 A, DESH. 

 (see below) PL xvii. fig. 7 ; Dent. Entails L., DESH. PI. xv. fig. 7, xvi. 

 fig. 2, GUERIN Iconogr., Annel. PL 3, fig. i, Cuv. R. Ani., ed. ill, Annel. 

 PL 7, &c. 



Comp. on this genus DESHAYES A natomie et Monographic du genre Den- 

 tale, Mem. dela Soc. d'Hist. not. n. Paris, 1825, pp. 321 378, PL 15 r8. 



Family VIII. AspidobrancMata. Shell clypeiform, in most 

 not turbinate, with very large aperture, incumbent on the pectinate 

 branchiae. Heart with two auricles, perforated by the rectum as in 

 AcepJiala. Organs of sex distinct, some individuals male, others 

 female. 



Lottia GRAY (Patello'ide QUOY and GAIM.). Branchia pectinate, 

 placed on the right side and forwards, often emerging beyond the 

 mantle. Shell conical, often thin. 



Note. A genus very similar to the Patellce, but different in the structure 

 of the branchiae. Comp. QUOY et GAIMARD Voyage de I' Astrolabe, Zoolo- 

 gie, ill. 1834, pp. 349 366. Sp. Lottia testudinaria, Patella testudinaria 

 L., LAM. ; Patella mrginea MUELL., Lottia pulchella FORBES. Comp. 

 Ann. of Nat. Hist. vm. 1841, pp. 404 406. 



not 



ALDER Ann. of Nat. Hist. vm. 1841, pp. 404 400. 



Parmophorus LAM. Shell oblong, oval, depressed, clypeiform, 

 turbinate, with margin entire, apex subincurved, not perforate. 



