FOSSIL PHYLLOCARIDA. 3 



II.-CARAPACE, BIVALVE. 



I. Pod-like. 



Arenig and Lin- ) , _, 



I a ^ j 1- Caryocarts, baiter. 1862. Pod-like ; elongate, narrow, smooth. 



Tremadoc, Silu- n 



rian, and Devo- \ 2. Ceratiocarig, M'Coy. 1819. Pod-like ; subovate, suboblong, &c. ; striate. 



nian (America). -' 



Upper Silurian. 3. Physocaris, Salter. 1860. Round. 



Lower SUurian. 4. Nothozoe, Barrande. 1872. Oval. 



Carboniferous. 5. Gryptozoe, Packard. 1886. Suboblong. 



Upper Silurian. 6. Xiphocaris, T, R. J. and H. W. 1886. (Only telson known.) 



Carboniferous. 7. CoZ/jocarJs, Meek. 1872. Subovate; strongly emarginate at one end (posterior). 



II. POD-LIKB : OCULATE.^ 

 Upper Silurian. 1. Emmelezoe, T. R. J. and H. W. 1886. Subovate. 



III. With Swellings (due to internal organs) in the Antebo-dorsal Eeqion, one 



OF WHICH, ON EACH VaLVE, MAY BE OCULAR.^ 



Devonian. 1. Ecliinocaris, Whitfield. 1880. Leperditioid. Segments spinose. 



Upper Silurian. 2. Aristozoe, Barrande. 1872. Leperditioid. 



— 3. Orosoe, Barrande. 1872. Leperditioid. 

 Devonian. 4. Elymocaris, Beecher. 1884. Leperditioid. 



— 5. Tropocaris, Beecher. 1884. Leperditioid. Wrinkled. 



Upper Silurian. 6. Ptychocaris, Novak. 1885. Leperditioid. Wrinkled. 



— T. ? Pliasga7iocaris, NoTak. 1886. (Only telson known.) 



IV. With Swellings in the Antero-ventral Region ; ocular tdberole not 



APPARENT. 

 Upper Silurian. 1. Gallizoe, Barrande. 1872. Leperditioid. 



V. CONCHIFEROIDAL ; PROBABLY ENCLOSING ALL THE ABDOMINAL SEGMENTS. 



Tremadoc. 1. Lingulocaris, Salter. 1886. Modioloid, and faintly ridged. 



Carboniferous. 2. Solenocaris, Meek. 1872. Pod-shaped, and concentrically marked. 



Silurian. 3. ? Orthonotella, Ulrich. 1882. Oblong. 



[ 4. Myoearis, Salter. 1864. Quadrangular, and ridged obliquely, 

 nian ? ) 



Carboniferous. 5. Leaia, Jones. 1862. Quadrangular, ridged obliquely, and concentrically 



marked. 



Devonian. Carboniferous. ■^ 



Triassic. Rhagtic. / 6. Estheria, Riippel. 1838. (True Phyllopod.) Like a bivalved 



Jurassic. Neocomian. C mollusc, and concentrically marked. 



Tertiary ? Recent. J 



' If the " ocular" swellings of the carapace be eye-spots, such a character would necessitate the 

 removal of these forms to a separate division. But the nature of these prominences is uncertain. 



