FISHES OF THE PHILIPPINE ISLANDS AND ADJACENT SEAS 487 



Order Chimaeroidei 



Snout prominent, soft, without proboscis. Claspers trifid, rarely- 

 bifid. 



Family CHIMAERIDAE 



Body elongate, rather robust anteriorly, tapering posteriorly to 

 point at tail. Head large, compressed, without proboscis. Mouth 

 small, inferior, upper lip deeply notched. Jaws with teeth confluent 

 into 4 bony laminae or tritors above, 2 below, receive impact on 

 edges. Nostrils confluent with mouth separated by narrow isthmus. 

 Free gills 3 and one-half gill each side. Gill rakers small. Isthmus 

 moderate. No spiracles. Notochord surrounded with narrow ring- 

 like segments. Cerebral hemispheres fused with olfactory lobes 

 distant from optic lobes. Skin naked, rarely somewhat prickly. 

 Lateral line open canal, usually with numerous branches anteriorly 

 or on head. Oviparous, egg-cases long, elliptical, with silky fila- 

 ments. Mature male with erectile "frontal holders" on forehead 

 and prepelvic tenacula. Dorsal usually divided, anteriorly short 

 and with very strong spine, grooved behind. Second dorsal long 

 and low. Caudal narrow, tapering, subcaudal with extended lobe. 

 Pectorals large, free, low. Ventrals abdominal, many rayed. Ma- 

 ture males with trifid claspers, rarely bifid. 



The living forms are remarkable for their striking appearance. 

 Most are found in deep water or cool seas. About 17 genera de- 

 scribed, all extinct and only Ghimaera persisting to recent time. 



Genus CHIMAERA Linnaeus 



Chimaera Linnaeus, Syst. Nat., ed. 10, voL 1, p. 236, 1758. (Type, Chimaera 



monstrosa Linnaeus, designated by Jordan and Gilbert, U. S. Nat. Mus. 



Bull. 16, p. 54, 1883.) (Poll, 1791, in Mollusca and Ochsenheimer, 1808, in 



Microlepidoptera precluded. ) 

 Chimoera Cxtvier, Tabl. Element, (an. 6), p. 317, 1798. (Type, Chimaera 



monstrosa Linnaeus.) 

 Chimera Rafinesque, Analyse de la nature, p. 92, 1815. (Type, Chimaera 



monstrosa Linnaeus.) 

 Chimaira Dum^kil, Mem. Acad. Sci. France, vol. 27, p. 155, 1856. (Type, 



Chimaera monstrosa Linnaeus.) 

 Plethodus Dixon, Fossils of Sussex, p. 366, 1850. (Type, Plethodus expansus 



Dixon, monotypic.) (Fossil.) 

 Hydrolagus Giix, Proc. Acad. Nat. Sci. Philadelphia, 1862, p. 331. (Type, 



Chimaera colliei Lay and Bennett, monotypic.) 

 Dipristis Geevais, Zool. Pal. G^n^rale, p. 240, 1869. (Type, Dipristis chimae- 



roides Gervais, monotj'pic.) (Fossil.) 

 Bathyalopex Collett, Arch. Naturv. Christiania, vol. 23, p. 5, 1901; Forh. Vid. 



Selskr. Christiana, No. 9, 1904, p. 5, 1905. (Type, Chimaera {Bathyalopex) 



miraiilis Collett, monotypic.) 



156861—41 32 



