24 CRANIID.E. 



** Hingeless. 



Family II. CKANI'IME, (CraniadcB) King. 



Body circular : arms spirally coiled, and not supported by 

 any shelly process or septum : attachment formed by the ad- 

 hesion of the lower valve, or part of it, to other substances. 



Shell circular or subquadrangular : upper valve conical or 

 cap-shaped : lower valve flat : muscular scars remarkably 

 strong and conspicuous. 



Our seas contain at present one only of this hingeless 

 group of Brachiopoda, which is distinguishable from all 

 the preceding kinds by the upper valve being conical 

 and the lower valve flat and attached, as well as in 

 neither valve being perforated. The shell is opened by 

 the action of the adjust or or protractor muscles; and 

 this takes place only to a very limited extent. Through 

 the Discinicla? there appears to be a passage to Anomia, 

 both of which have a byssal peduncle issuing out of a 

 hole or slit in the lower valve for attachment to other 

 substances. 



Genus I. CRANIA* Retz. PL I. f. 3. 



As the family contains but this single genus, it is un- 

 necessary to recapitulate the characters. 



1. Crania ano'malaI-, Miiller. 



Patella anomala, Mull. Zool. Dan. Prodr. p. 237, no. 2870. C. an&mala, 

 F. & H. ii. p. 366, pi. lvi. f. 7, 8 ; (animal) pi. U. f. 2, as C.Norvegica. 



Body of a milk-white colour, tinged with yellow or brown : 

 mantle very thin : arms thick and fleshy ; cirri rather nume- 

 rous, stiff, and rather long. 



* From a fancied resemblance of the inside of the lower valve to the 

 front of a human skull, 

 f Irregular. 



