BATHYMETRINAE 165 



SO regular as those of P. longipinna (see below, p. 169). The ventral edge of the centro- 

 dorsal is produced into corners interradially. 



Cirri ca. XLV, 17-19 (Fig. 10 a). The first segment is very short, the second as long 

 as broad. The third segment is nearly twice as long as broad, a little constricted in the 

 middle, and considerably wider distally than proximally. The fourth, fifth and sixth are 

 the longest segments, twice to two-and-a-half times as long as broad. They are slightly 

 constricted in the middle and have expanded distal ends. The seventh and eighth 

 segments are twice as long as broad and considerably wider distally than proximally. 

 They and the remaining segments are laterally compressed. The ninth to the twelfth 

 are of roughly equal length, but each is a little wider distally than the one before it. 

 All the distal segments are a httle longer than broad. The distal part of the cirrus is 

 considerably wider than the median part. The opposing spine is strong; it stands out 

 at right angles to the penultimate segment, its inner edge straight, its outer convex. The 

 terminal claw is strong and curved. 



The radial is very short (Fig. 10 b). The costal is much longer; it is narrower distally 

 than proximally and it is deeply incised by the posterior projection of the axillary which 

 makes a projection with it. The costals are not in lateral contact. The axillary is about 

 as long as broad ; the proximal edges are straight, the distal deeply concave. 



Syzygies are very numerous. The first is between the third and fourth, the second 

 between the ninth and tenth, the third between the fourteenth and fifteenth brachials. 

 There are the following exceptions : on one arm the first, on another the second syzygy, 

 is between the eighth and ninth brachials ; on another arm the third syzygy is between 

 the twelfth and thirteenth brachials. 



The first brachials are short, their inner edges shorter than the outer and not in 

 apposition. They are strongly incised by the second brachials which are slightly longer 

 than broad, roughly triangular with the inner and distal edges concave, the outer convex. 

 The interior edge of the first syzygial pair is longer than the exterior and greater than 

 the width of the ossicles. The brachials between the first and the second syzygy, the 

 fifth to eighth, are roughly rectangular in shape ; the fifth is slightly broader than long 

 or is square while the others are slightly longer than broad. Those between the second 

 and third syzygies are longer on one side than the other and a little longer than broad. 

 The distal brachials are more elongate and rectangular (Fig. 10 c). 



The radials, primibrachs and first four brachials are smooth. The distal edges of the 

 following brachials are slightly raised and are produced into spines which are small in 

 the lower part of the arm but larger and conspicuous on the outer brachials. 



In all the pinnules the first two segments are short ; the others are longer than broad 

 or elongated, with their distal edges strongly flared and spiny so that the joints have 

 a swollen appearance. The oral pinnules are the longest, nearly twice as long as the 

 first genitals and about one and one-third times as long as the outer pinnules (Fig. lod). 

 Pi is not complete on any arm. P^, P, and P^ are of 18-19 segments, 8 mm. long. 

 P3, the first genital, is oi ca. 10 segments and about 4 mm. long (Fig. 10 e); P5 resembles 

 it but has a larger gonad. Pg is of 14 segments about 6 mm. long, and Pg , the last genital 



