CRUSTACEA. 639 



this crustacean ; from this ridiculous popular fancy the Bpecific name goose- 

 mussel is derived. 



Pollicipes LEACH (and Scalpellum ejusd.), Polylepas BLAINV. 

 Peduncle rough, squamose. Shell compressed at the sides, with 

 valves subcontinuous, unequal, thirteen or more. 



Sp. Pollicipes scalpeUum LAM., Lepas scalpellum L., GUEEIN Iconogr. 1. 1. 

 fi g- 4 ; Pollic. mitdla, Lepas mitella L., KUMPH. Ami. RariteitTcarn. Tab. 

 47, fig. M, GUERIN 1. 1. fig. 3, &c. 



Gfymnolepas BLAINV. Conchoderma OLFERS. Mantle naked, 

 without valves, or with rudiments of valves, remote from each other. 



Cineras LEACH, LAM. Calcareous pieces five distinct, joined by 

 membrane, small, with one dorsal, two above the aperture of mantle, 

 two others below that aperture. 



Sp. Cineras vittata LEACH, Lepas coriacea POLI Testae, i. Tab. vi. fig. 20, 

 GUERIN Iconogr. 1. 1. fig. 5 ; in the Mediterranean sea. 



Otion LEACH. Two lunated valves at the margin of the aperture 

 towards the peduncle. Body with two tubular ear-like appendages 

 pervious at the apex. 



Sp. Otion Cuvierii, Lepas aurita L., POLI 1. 1. fig. 21, GUERIN Iconogr. 1. 1. 

 fig. 6. 



Alepas RANG. Mantle without any calcareous pieces, subpellucid, 

 continuous with peduncle. 



Sp. Alepas fasciculata LESSON, Anatife jaune sans coquille MARTIN SAINT- 

 ANGE Mem. sur les Cirripedes, Tab. I. GUERIN Iconogr. 1. 1. fig. 8, Alepas 

 squalicola LOVEN, dfversigt of konigl. vet. ATcad. Forhardlingar. 1844, 

 pp. 192, 193, Tab. III. (in this species, that lives parasitically on sharks, 

 the feet also are soft, and without bristles). 



Note. On the fossil species, which are chiefly found in chalk strata, of 

 Anatifa and Pollicipes comp. STEENSTRUP in KROEYER'S Tidskrift i. 1837, 

 pp. 358 366, ii. 1839, PP- SQ^ 4 X 5> an( i on the fossil Lepadidce of Great 

 Britain, C. DARWIN'S Monograph, 1851, printed for the Palseontographical 

 Society. 



[From the investigations of DARWIN, recorded in his two admir- 

 able memoirs so often cited, we learn that his subclass of Cir- 

 ripeds contains forms that differ greatly from those of the JBala- 

 noidea and Lepadicea and are much less perfect in their organisation. 

 He divides the Cirripeds into three orders the Thoracica, Abdomi- 

 nalia, and Apodes, the limbs or cirri being thoracic in the first, 

 abdominal in the second, and entirely absent in the third. In the 



