738 REPORT OF COMMISSIONER OF FISH AND FISHERIES [40] 



one capillary ; the other stout, spinous ; all other setae capillary. Each 

 ramus, after the first segment, furnished with a transverse plate, thin, 

 lateral, projecting, outer margin lobed. All segments biramous. 



Thaumastoma singulaee n. sp. 



(Pl. VII, Figs. 85-94.) 



Head composed of two parts; anterior two-thirds flattened (fig. 85), 

 nearly quadrangular, slightly emarginate in front ; posterior third 

 rounded, convex, bearing two pairs of minute black eyes; destitute 

 of appendages. 



The proboscis was seen extended to a length about equal to that 

 of the head ; the incisions dividing it into lobes were observed to run 

 back about one-half this length. In alcohol the proboscis was nearly 

 Avithdrawn, showing pnly its anterior end (fig. 86) ; its inner surface 

 was densely ciliated. 



The dorsal ramus of the first segment is composed (fig. 85) of two 

 stout, conical cirri, longer than the head; the upper of these points 

 forward ; the lower forward and outward ; between their bases rise two 

 distinct bundles of capillary setaj, which are directed forward, and reach 

 beyoud the head. The lower ramus of the first segment consists of a 

 transverse, convex, fleshy lobe, terminating above in a short, stout, 

 blunt, rounded process ; in front of this plate are two rows of setae; those 

 forming the anterior series (fig. 93) similar to the posterior (fig. 92), only 

 longer and more delicate, but still having rather the form of spines than 

 of capillary setse, these anterior setae are very light colored, nearly 

 white ; the posterior series is composed of G-S stout yellow spines (fig. 

 92). 



The second segment has its dorsal ramus composed of a depressed 

 fleshy lobe (not seen in the figure, which is a front view), from which 

 arises a fan of capillary setae (figs. 87, 94), while in front of this lobe is 

 a thin, projecting jilate, divided along its outer margin (fig. 87) into six 

 unequal, bluntly rounded lobes. 



This lower ramus is much like the corresponding ramus of the first 

 segment, but lacks the superior process. In this ramus is a posterior 

 row of black spines, similar to those of the first segment, except in color, 

 and an anterior series of very fine capillary setae, much shorter and more 

 delicate than the capillary setae of the segments behind, shorter even 

 than the spines of the same ramus. Behind the second segment all the 

 setae are capillary and arise from more or less well-marked rounded 

 lobes. 



On the third segment a digitated plate runs down the side of the 

 body, in front of both rami. It has twentj^-one lobes (fig. 88) along its 

 outer margin, and runs from above the dorsal ramus to below the ven- 

 tral. On the fourth segment there are two such lobes (fig. 89). After 

 the fourth segment the dorsal lobe steadily shortens, till on the seven- 



