FISHES FROM NORTHEASTERN PACIFIC— CHAPMAN 513 



insertion of the ventrals. The caudal pigment blotch extends com- 

 pletely across the base of the caudal fin. In addition to the segmen- 

 tally arranged bars of pigment that are found below the lateral line 

 on the smaller specimen there is a similar series above the lateral line 

 that is prominent anteriorly but fades out before the origin of the 

 dorsal. The rays of the pectoral are larger and extend beyond the 

 base of the ventrals. The ventral rays are also much longer than 

 those in the smaller specimen. They extend to the end of the anal 

 fin. The dorsal and anal fins are both present, although their rays 

 are not yet fully developed. The origin of the adipose fin can barely 

 be made out in the median fin fold remaining between the dorsal and 

 the caudal. The ventral median fin fold has disappeared. The large 



Figure 61.— Macropinna microstoma, new genus and species: Specimen 16.5 mm long, from station 593B. 



rays of the caudal approach the form of the older specimens but the 

 small rays dorsally and ventrally have not yet become differentiated. 

 The intestine still originates from the right side of the stomach, but 

 the pylorus has turned dorsally so that the intestine makes a 

 half turn around the stomach. The posterior dextral flexure of the 

 large intestine still lies under the sixth pigment bar behind the ventral 

 base, but the small intestine has coiled back nearly to the level of the 

 ventral origin. It has likewise lengthened. The anus has, in the 

 meantime, moved forward until it lies under the eighth pigment bar 

 behind the ventral origin and only a short distance posterior to the 

 intestinal flexure. 



Length without caudal 16.5 mm. Proportions in length without 

 caudal: Length of head 2.8; greatest depth 5.1; snout to origin of the 

 dorsal 1.4; snout to insertion of ventrals 2.1; snout to origin of anal 

 lA. Proportions in the length of the head: Length of upper jaw, 4.0; 

 diameter of eye 4.8; length of caudal peduncle 4.0; depth of caudal 

 peduncle 3.4. There are 37 segments in the body. 



25-MILLIMETER STAGE 



The specimen from station 293B, 25 mm in length without caudal, 

 has practically attained the adult form and characters but is important 

 in that it still retains some of the larval characteristics. The seg- 

 mentally arranged pigment bars below and above the lateral line, 

 although faded, are still present. The peritoneum has become heavily 



