TRIASSIC FISHES FROM SPITZBERGEN 
3°5 
Explanation of index letters. 
D, dorsal fin; Ext, extrascapular; Fr, frontal; Op, operculum; Pa. parietal; Po, preoperculum; 
Rbr, branchiostegal ray; Scl, supracleithral; Sop, suboperculum; Stemp.it, supratemporo-intertemporal; 
ifc, infraorbital sensory canal; l, lateral canal; md, middle pit-line of head organs; poc, preopercular 
sensory canal; s. com, supratemporal transversal commissure between the cranial sections of the two 
lateral canals; soc, supraorbital sensory canal. 
Plate 28. 
Fig. 1. Boreosomus reuterskioldi n. sp., impression of the ventral side ( P. ug ). Somewhat magnified. 
» 2. Platvsomus nathorsti n. sp., some scales ( P. 142b), preserved as impression of the medial surface- 
» 5. Perleidus woodwardi nom. nov., posterior portion of fish with dorsal and anal fins ( P . 18S). 
Explanation of index letters. 
A, anal fin; D, dorsal fin; Md, mandible; Mg, median jugular plate; Mx, maxillary; Op, oper¬ 
culum; Pc , pectoral fin; Po, preoperculum; Rbr, branchiostegal rays; Rd, endoskeletals radials in the 
dorsal fin; Sop, suboperculum; V, ventral fin. 
Plate 29. 
Fig. 1. Boreosomus sp., body and incompletely preserved specimen (P. 120 ) showing the position 
of the dorsal fin. 7 / 10 . 
» 2. » » scales from the lateral surface of the abdominal region ( P. 131b). 3 / 2 . 
» 3. » » scales from the ventral parts of the abdominal region preserved as impressions 
on the stone (P. 131a). 3 / 2 . 
» 4. Acrohabdus latistriatus n. sp., abdominal region and parts of the head (P. 170). 
Explanation of index letters. 
D, dorsal fin; Md, mandible; Mg, median jugular plate; Mx, maxillary; Op, operculum; Pc, 
pectoral fin; Po, preoperculum; Rbr, branchiostegal rays; Scl, supracleithral; Sop, suboperculum. 
Plate 30. 
Fig. 1. Acrorhabdus asplundi n. sp., parts of head and abdominal region (P. 173). 
» 2. » » » » scales (P. 173). 3 / 2 . 
» 3. » latistriatus n.sp., scales from the lateral surface of the abdominal region (P. 170). 2 / r 
» 4. » » » » scales from the ventral part of the abdominal region (P. 170). 2 / r 
>>5. » » » » scales from the dorsal part of the abdominal region rather close 
behind the head (P. 176), 2 / r 
Explanation of index letters. 
Ang, angular; Cl, cleithrum; De, dentalo-splenial; Mx, maxillary; Op, operculum; Pc, pectoral 
fin; Po, preoperculum; Rbr, branchiostegal rays; Scl, supracleithral; Sop, suboperculum. 
Plate 31. 
Fig. 1. Acrorhabdus bertili n. sp., head seen from the right side (P. 174). The cheek plates are totally 
and the opercular plates are almost totally weathered away and by 
far the greater part of the neurocranium also very incompletely- 
preserved. 
