260 AMERICAN JOURNAL 



Mantle edge thick, with a single row of rather stout papillae 

 interspersed with smaller ones irregularly disposed ; sides of foot 

 smooth ; foot oval, thin, rather small ; muzzle and edges of foot 

 dusky ; back of head, bases of tentacles and mantle edge yellow- 

 ish. Head stout, short, rounded ; tentacles short, small, rapidly 

 tapering to a sharp point; in the alcoholic specimens invariably 

 hooked, or with the tips recurved. Muzzle rather transverse, 

 surface radiately papillose, frill conspicuous, smooth and even. 

 Gill very large and long, usually protruded across the neck nearly 

 to the mantle edge. Anal and infra-anal apertures on a promi- 

 nent pointed tubercle; renal not observed. Uncini larger than 

 usual. Formula, ° 



2(2— 1-1— •^)2> 



This species was obtained it abundance at Amboyna, by Mr. 

 Bickmore. 



The muscles whicli retract the radula are transversely striated. 

 See Silliman's Am. Journ. Sci. and Arts, Feb., 1871, p. 123. 

 Since that time a similar state of things has been observed in 

 Collisella paleacea^ Gld. These are the first instances of such 

 fiber noticed in the class Gasteropoda. 



Genus LOTTIA, Cpr. ex Sby. 



Lottia (Gray MSS.), Sby., Gen. Shell, part 42, fig. 1. Reeve, 



Conch. Syst. f. 1, 1842. 

 Tecturella, Cpr., Smithsonian Check List, W. C. Shells, 1860, 



p. 3, No. 176. Ptep. Br. Assoc. 1861, p. 137. 

 Tecturma, Cpr., Smiths. Bep. 1860, p. 219. Lect. Moll. Ind. 



Ed. p. 71 = err. typog. for Tecturella ? 

 Lecania, Cpr. MSS. 



Lottia^ Cpr., Journ. de Conchyl. vol. xiii, p. 140, 1865. Am. 



Journ. Conch, vol. ii, p. 342, 1866. Sup. Rep. Brit. 



Assoc. 1863, p. 650, No. 249. 



Animal with a single cervical branchia ; also furnished with a 



branchial cordon of laminae between the mantle edge and the 



foot, extending as far forward as the adductor muscle on each 



side, and continuous behind. Teeth and muzzle frill as in Colli- 



sella. 2 



1(2— 1-1— 2)1 ■ 



Type LoTTiA gigantea. Plate 15, fig. 20. 



Lottia gigantea, Sby. ajmd Gray. Gen. Sh. pt. 42, f. 1. 

 Ac77ura scutum, auct. non Esch. nee D'Orb. 

 Tecturella grandis (Gray) Cpr. 



The shell of this species has been fully described by Dr. Car- 

 penter in his admirable paper on the Acmaeidae, before cited ; it 

 only remains to give a few additional notes on the animal. I 



