806 BULLETIN 82, UNITED STATES NATIONAL MUSEUM VOLUME 1 



The 5 arms are from 80 to 110 mm. long. The first brachials are oblong, about 

 twice as broad as long, or even shorter, with the anterolateral corners produced in- 

 wardly in the form of a rounded process. The second brachials are similar, but usually 

 slightly longer. There is a more or less pronounced synarthrial tubercle on the articula- 

 tion between the first and second brachials. The second brachial bears a pinnule on 

 one side and an anterolateral projection similiar to that of the first brachial on the other. 

 The third brachial is oblong, about twice as broad as long. The first syzygial pair 

 (composed of brachials 4 + 5) has the hypozygal (fourth brachial) wedge-shaped and 

 the epizygal (fifth brachial) oblong, the two together usually being in width rather 

 more than the lesser and less than the longer side; in some individuals the width slightly 

 exceeds the longer side. The following brachials to the eleventh are wedge-shaped, 

 broader than long, those succeeding becoming obliquely wedge-shaped and nearly, or 

 quite, as long as broad, later less obliquely wedge-shaped again and proportionately 

 longer, and terminally moderately wedge-shaped or almost oblong, about twice as long 

 as broad, with the articulations prominent. The arms are smooth, the brachials not 

 overlapping. 



Syzygies occur between brachials 4 + 5, 9 + 10 to 11 + 12 (usually 10 + 11), 13 + 14 

 to 16 + 17 (usually 15 + 16), and distally at intervals of from 2 to 8 (usually 3 to 5) 

 muscular articulations. 



P! is short, weak, and slender, in a medium-sized individual 6.5 mm. long, with 25 

 segments, all of which are short, the proximal three or four not so long as broad and 

 the following gradually becoming slightly longer than broad. The segments in the 

 basal third have their corners cut away; this feature gradually disappears in those fol- 

 lowing, which become cylindrical. P 2 is slender, 9 mm. long, composed of 25 segments, 

 of which the first two are very short, the third is about as long as broad, and those fol- 

 lowing very gradually become elongated, distally reaching a length of about twice the 

 width. There is sometimes a gonad on the fourth to sixth segments. P 3 is 10 mm. 

 long, rather stouter than P 2 , composed of 24 segments, of which the first two are very 

 short and those following gradually become elongated, reaching a length of about twice 

 the width distally. The corners of the 3 or 4 lowest segments are cut away, and from 

 the fourth or fifth onward the segments have rather prominent articulations. There 

 is a large rounded gonad on the fourth to eighth segments. The following pinnules 

 increase in length, P 5 being 11 mm. long and P 6 12 mm. long; the latter is composed of 

 25 segments which resemble those of P 3 except that those beyond the gonad are more 

 slender and more elongated (three or four times as long as broad) with more expanded 

 articulations. P 6 is intermediate between P 3 and P 6 , though more like the latter. The 

 following pinnules, while remaining of about the same length, come to have more elon- 

 gated segments, and the gonad gradually decreases in size; with the decrease in size of 

 the gonad the pinnule comes to have a uniform taper, losing the sudden diminution in 

 diameter at the outer extremity of the gonad. P 10 is 11 mm. long, with 22 segments, 

 of which the first is short and crescentic, the second is about as long as broad and 

 slightly trapezoidal, and the remainder rapidly become elongated with enlarged articu- 

 lations, and exceedingly long and slender distally. The gonad is small, occupying only 

 the fourth to sixth segments. The gonads persist to about Pi 3 . None of the distal 

 pinnules are preserved entire; they resemble P :0 , but except for the first two the seg- 

 ments are somewhat more elongate, and the articulations rather more expanded. 



