Report of the State Geologist. 



Mil 



causes than restricted powers of self-distribution, in co-operation 

 with ;i given capacity of resistance to physical forces. 



An important factor in their distribution is the influence of 

 beat and cold, to which the brachiopods are evidently sensitive; 

 a fact which makes itself apparent in their geographical dissemi- 

 nation. There are some species {Semithyris psittacea, Liothyrina 

 arctica^ Terebratdla Spitzbergensis) which flourish best in the 

 cold waters about the north pole, and never transgress into the 

 warmer seas where the brachiopods are most prolific. At the 

 same time there area tew species that are world-wide in their 

 distribution {Liothyrvna vitrea, var. mi/nor^ Terebratvlma caput- 

 s, rpentis\ and, as CEhlebt observes, these are species which also 

 po>^sess the greatest bathy metric range. 



The following table of the Geographical Provinces and the spe- 

 cies embraced within them has been largely drawn from that 

 compiled by OEhlert in Fischer's Manuel de Conch yliologie. 

 This may be studied in connection with the accompanying map 

 of the World, upon which is plotted the distribution of living 

 species. 



Arctic Province: 

 Atretia gnomon. 

 Crania anomala. 

 Discinisca atlantica. 

 LiothyHna arctica. 

 Macandrevia cranium. 

 Dallina septigera. 

 Magellania tenera. 



Rhynchonella (Hemithyris) psittacea. 

 Terebratalia frontalis. 

 Terebratella Spitzbergensis. 

 Terebratulina caput-serpentis. 



Boreal Province: 



Atretia gnomon. 



Cistella cistellula. 



Crania anomala. 



" var. alba. 



Laqueus Californicus (Megerlina Jef- 

 frey si.) 



Macandrevia cranium. 



Dallina septigera. 



Rhynchonella (Hemithyris) psittacea. 



Terebratella Frielii. 



T. Labrador ensis. 



T. Spitzbergensis. 



13 



Terebratalia transversa. 

 Terebratulina caput-serpentis. 

 T. unguiculata. 



Lusitanian Province: 

 Cistella cistellula. 

 C. cuneata. 



C. neapolitana. 



Crania anomala. 

 Discina striata. 

 Discinisca atlantica. 

 Eucalathis ergastica. 

 E. Ifurrayi. 



E. tuberata. 



" " var. mediterranea. 



Gwynia capsula. 

 Liothyrina sphenoidea. 

 L. vitrea. 



" " var. minor. 



Macandrevia cranium. 

 Dallina septigera. 

 Megathyris decollata. 

 Mi'thlfeldtia truncate/. 



" " var. monstruosa. 



Platidia anomoides. 

 P. Davidsoni. 



