56 Moll. 
MOLLUSCA. 
sides into one unpaired plate in Lepeta , while in the latter two, in Lepe- 
tella one, and in Pectinodonta no marginal plates are developed. He gives 
an analytical table of all known genera with their dental formula, divid- 
ing this Order as follows 
Sub-Order Abranchiata , no external branchiae; embryonic shell spiral. 
Only family Lepeticlce, subfamily Lepetince, gen. Lepeta, Gray, 
including Pilidium (Forb.) and Cryptobranchia (Midd.), and 
subfam. Lepetinellince, gen. Lepetella , Verr. 
Sub-Order Proteobranchiata , external branchiae ; embryonic shell conical. 
Fam. Acmceidce, a plumose cervical branchia ; no rhachidian tooth ; 
gen. Pectinodonta , Scutellina , Acmcea , Collisella , Lottia , 
Scurria. 
Fam. Patellidce, no cervical branchia, but a cordon of branchial 
lamellae on both sides. 
(a) Branchial cordon complete ; gen. Ancistromesus, with a 
rhachidian tooth ; Patella , Patinella, and Nacella without it. 
(b) Branchial cordon interrupted in front ; gen. Ilelcion , Helcio- 
nxscus, and Patina , all without rhachidian tooth. 
P. U. S. Nat. Mus. iv. (April, 1882) pp. 411-414 ; abstract in Ann. N. H. 
(5) x. pp. 24-26. 
Tectura (Milne-Edwards) has priority over Acmcea (Esch.) ; T. rugosa , 
pusilla, aclunca , and galeola , spp. nn., Jeffreys, P. Z. S. 1882, pp. 671 
& 672, pi. 1. figs. 2-5, Atlantic ‘Porcupine’ Expedition. 
Patella solandri (Colenso, Tasm. J. of Nat. Sc. ii. [1841 ?]), Tokomara 
Bay, North Island of New Zealand, Colenso, Tr. N. Z. Inst. xiv. p. 168 ; = 
Acmcea fragilis (Chemn.), Kirk, N. Z. J. Sci. i. p. 213. 
Pectinodonta, g. n. Allied to Scutellina, blind, dentition composed of 
one large pectinate lateral plate on each side of the median line. P. ar- 
cuata , sp. n., Dali, P. U. S. Nat. Mus. iv. p. 409, St. Thomas and Sta. 
Lucia, West Indies, 226 fath. ; Anu. N. H. (5) x. pp. 21 & 22. 
LEPETIDiE. 
Propilidium scabrosum , pertenue , and compressum , spp. nn., Jeffreys, 
P. Z. S. 1882, p. 674, pi. 1. figs. 6-8, Mediterranean and Atlantic, ‘ Porcu- 
pine ’ Expedition. 
Lepetella tubicola , Yerrill & Smith, Am. J. Sci. (3) xx. [1880], p. 391 ; 
Dali ; P. U. S. Nat. Mus. iii. p. 375 and iv. p. 408. Shell and anatomy as 
in Lepeta, but eyes distinct, radula provided with true lateral teeth and 
scale-shaped uncini ; nucleus of the shell subspiral. Dali proposes a 
new subfamily, Lepetellince for it. Found in old tubes of Hyalincecia , 
off Martha’s Vineyard, South of Cape Cod; Verrill, Tr. Conn. Ac. v. 
p. 534. 
[This genus was by mistake wrongly placed in the Cerithiopsidcc in the 
preceding Record, Moll. p. 46 ] 
