FOSSIL PHYLLOCARIDA. 



Arenig and Lin- 

 gula-flags. 



Tremadoc, Silu- 

 rian, and Devo- 

 nian (America). 



Upper Silurian. 



Lower Silurian. 



Carboniferous. 



Upper Silurian. 



Carboniferous. 



II.-CARAPACE, BIVALVE. 



I. Pod-like. 



• 1. Oaryocaris, Salter. 1862. Pod-like ; elongate, narrow, smooth. 



2. Ceratiocaris,M.'Coy. 1849. Pod-like; subovate, suboblong, &c. ; striate. 



3. Physocaris, Salter. 1860. Eound. 



4. Nothozoe, Barrande. 1872. Oval. 



5. Cryptozoe, Packard. 1886. Suboblong. 



6. Xiphocaris, T, E. J. and H. W. 1886. (Only telson known.) 



7. Colpocaris, Meek. 1872. Subovate; strongly emarginate at one end (posterior). 



II. Pod-like : Ooulate. 1 



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



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



OF WHICH, ON EACH VALVE, MAY BE OCULAR. 1 



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



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



— 3. Orozoe, Barrande. 1872. Leperditioid. 

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



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



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



— 7. / Phasganocaris, Novak. 1886. (Only telson known.) 



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



APPARENT. 

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



V. Conchlferoidal ; probably enclosing all the Abdominal Segments. 



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



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



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



Sdurian or Devo- ") ^ MyocariS} Salter> 1864 . Quadrangular, and ridged obliquely. 



nian ? ) 



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



marked. 

 Devonian. Carboniferous. "\ 



Triassic. BhEetic. / 6. Estheria, Eiippel. 1838. (True Phyllopod.) Like a bivalved 



Jurassic. Neocomian. C mollusc, and concentrically marked. 



Tertiary ? Eecent. J 



1 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. 



