106 THE AMERICAN MONTHLY [May 
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Dorsal spine straight; lorica ovate unisetatus 
45, DiascHiza. II., 77. Sup. 37. 
Dorsal cleft narrow; the edges parallel, (a) 
Dorsal cl, do., diverging slightly in front.lacinulata. Weber, 545 
Dorsal cleft narrow ; closedin front, gaping behind, (d) 
Dorsal cleft wide throughout, (e) 
Toes blade-shaped, (b) 
Toes not blade-shaped, (c) 
Toes abruptly shouldered; dorsum squarely gibbous....cupha. Sup 
Toes even; body gibbous and swollen behind... 200. hoodii 
Toes even; body thick, front widest ; cleft ridged peta 
Marine. Lorica pyriform; head beaked fretalis. Sup 
Lorica flexible, constantly wrinkling ; minute, 1-350 inch..exigua 
Lorica not flexible, decurved; toes long, slender... valga 
Lorica do., ellipt’1; toes long,stout; trophi proj.ramphigera. Sup 
Head brdr. than body ; face very oblique..megalocephala.Q,’95, 123 
Head globose, prominent; lorica laterally cordate..acronota. Sup 
Head large, prominent; body cylindric, compressed....semiaperta 
Body subcylindric; toes thick, obtuse... 1... tenuior © 
Body subpyriform ; a ring girdling the round front ; toes 
glender; ACH re a ae acs globata. Sup 
46. Dipiax. II., 81. 
Lateral outline nearly a parallelogram... compressa 
Lateral outline ovate; transverse section triangular... trigona 
47. SALPINA. II., 82. Sup. 38, 
Lorica more or less extensively stippled, (b) 
Lorica not stippled, (f) 
Occipital spines none, (c) 
Occipital spines two, (e) 
Lorica w. stip’l’d collar ; pect’1 spines short, upt’n’d hooks. similis* 
Lorica w. do. ; pectoral spines short, not hooked... ventralis, Sup 
Lorica-surface more or less stippled, (d) 
Pectoral spines straight; alvine 2, short, recurved... brevispina 
Pectoral spines incurved; alvine long, incurved........ eustala 
Pect’1 spines 2-p’nt’d; teeth 2rows in each uncus(?)polyodonta.Sup 
Occip’1 spines mov’ly jointd to lorica ; posterior sp.no, macrocera+ 
Occip’1 sp.not j’ntd; alvine 2, rec’rv’d, sinus wide, deep..mucronata 
Occip’1 spines do.; alvine decurved, sinuses straight........ spinigera 
Occip’1 spines do.; alvine stout,sinus angular. Marine..marina. Sup 
Occipital spines none, (g) 
Occipital spines two, often short, (h) 
Lumbar spine straight, shorter than alvine............... macracantha 
Lumbar spine curved, longer than alvine. Australia........ cortina 
* Stokes. Ann. & Mag. Nat. Hist., 1896, 24. 
+ Jennings. Bul. Mich. Fish Com., 1894, 22. 
