82 'I'lIK ( IIISMorXKA i( IllMAKItOlDSj. 



^ills, unilcd wilh llu' skin distally; opcrciila rmliini'iilary. Spiracles absent, 

 except ill certain ciiihryniiic stages. Dental laminae in three ])airs, vomerine 

 and i)alatine above and mandibular below. Brain massed posteriorly, more 

 distribntcd forward, hemispheres distant from the ojitic lobes and attached to 

 them l)y a nerve-lik(> thread. Vertebrae imperfect, coalescent anteriorly. 

 Sheath of th(> notocliord not segmented. An erectile dorsal fin and spine the 

 basalia of whicii are articulated to a consoliilation of the neural spines above the 

 pectoral fins. Oviparous. Male on approaching maturity developing claspers 

 and a frontal tenaculum and two prepelvic tenacula adapted for clinging to the 

 tail and the fins of the female. In some species the wiile l)asal articulation 

 of the frontal tenaculum jirevents motion laterally antl the hooked spines 

 below its forward end are met by other sharp spines from within the cradle or 

 receptaculinn, thus intlicating decisively the manner of use and the purpose of 

 the organ. Skin naked in adults, a series of small spines, arranged in two rows 

 along the middle of the liack and on the top of the head, aid the escape from the 

 egg shell. 



"OO 



Snout prominent, soft, without a proboscis 



Brain with olfactories and hemispheres close together 

 Notocliord sui-rounded Ijy rings 



Teeth with tritors on their edges 



Claspers of male tritid, rarely bifid . . Chimaeridae 



Snout producetl into a long beak 



Brain with olfactories and hemispheres widely separated 

 Notochord with rings 



Claspers simple ...... Rhinochimaeridae 



Snout produced into a leaf-shaped, flexible appendage 



Brain with olfactories ami hemispheres widely separated 

 Notocliord without rings 



Teeth with tritors on their sides 



Clasjiers sinijile ...... Callonjnchidae 



Chimaeridae. 



Chiincrin Rafinksquk, IM.'i, AiKil. N;il., \i. 92 (= ChiiiuiiTa ;ui<l Mnrinyrus, = suhfam.). 

 Cliiniaerac Thien., 1S28, ZooloKio, p. 412 (= Chimaeru and Callorliynchus). 

 C himiwridac BoN.\p., 1831, Saggio, p. 98, 121 (= Chimapra ami CaUorhylll■!lU!^). 

 Chinimridae Gaum., 1901, I'roc. N. E. Zoul. Club, 2, ]>. 7(1 ( = t'liiiiiaiTa). 



Head moderately jiointed, without a proboscis. Body compressed, taper- 

 ing to a point at the tail. Pectoral fins large, free. First dorsal hn short, with 



