Pisces. 177 



TREMATOMUS, gen. n. 



Differing from Notothcnia in the scapular fenestra being pierced 

 in the scapula instead of between the latter and the coracoid. 



Synopsu of the Sioecics. 



I. Interorbital width 3 to Sg times in length of head; lower jaw projecting 



beyond upper ; gill-rakers 18 to 20 on lower part of anterior arch. 



D. VI-VIII, 32-36: A. 32-33; Sq. 90-100 3-^; lateral 



lines strongly marked, tubular 1. neivnesi, sp. n. 



D. V-YI, 3-1-37 ; A. 31-33 ; Sq. 97-110 ; lateral lines ill- 

 defined 2. horchgrevinki, sp. n. 



II. Interorbital width 4^ to 65 times in length of head ; lower jaw not projecting 



beyond upper ; gill-rakers 12 to 15 on lower part of anterior arch. 

 D. V-VII (usually YI), 38-41 ; A. 34-35 ; Sq. 65-75 ^^ ; 



interorbital region scaly 3. hansoni, sp. n. 



D. IV-VI (usually V), 35-38; A. 32-35; Sq. 66-80 ~; 



interorbital region naked or with a few scales 4, hernacchii, sp. n. 



As regards the skeleton, which I have been able to examine in 



the four species, the characters are essentially the same, except that 



the ossification is stronger, and the skull more massive, in the species 



of Group I. than in those of Group II. The parapophyses begin on 



the second or third vertebrae and soon become very strong; they 



bear the rib and the epipleural, which are inserted close together. 



Number of vertebrae : — 



T. newnesi. 20 + 34 = 54 



T. borchgrevinki. 20 + 32 = 52 



T. hansom. 21 4- 35 = 56 



T. hernacchii. 17 + 35 = 52 



3. Tkematomus newnesi, sp. n. 



(Plate XL) 



Depth of body 4 to 4f times in total length, length of head 

 3^ to 4 times. Diameter of eye 3 (young) to 4 times in length of 

 head, interorbital width 3 to 31 times ; maxillary extending to below 

 centre or posterior third of eye ; lower jaw projecting beyond the 

 upper ; upper surface of head naked ; cheek and opercle densely 

 scaled. Gill-rakers long and slender, 18 to 20 on lower part of 

 anterior arch. Dorsal VI-VIII,^ 32-36 ; longest rays f to 1 length 

 of head. Anal 32-35 ; longest rays I length of head. Pectoral 



1 Out of 70 specimens, 48 have VII, 19 have VllI, and 3 have VI. 



N 



