CRUSTACEA COPEPODA. II. 7 
much beyond the end of the inner branch. — Maxille (fig. 2 f) rather slender; dactylus with claw much 
curved. — Maxillipeds (fig. 2 g) rather slender; dactylus with claw only a little longer than the basal part, 
and the claw considerably longer than the dactylus. (Fifth legs lost). 
Length 0.86 mm. 
Remarks. — A. intermedium is abundantly distinguished from every species figured by Giesbrecht 
and Sars by the relative length of the ten distal joints in the slender antennule, together with the maxillule, 
the narrow genital segment, the relative length of the other abdominal segments and the caudal rami. ‘The 
differences between this species and the two following forms are pointed out below. 
Occurrence. — Taken by the “Ingolf’”’ at a single station. 
Davis Strait: Stat. 25: Lat. 63°30’ N., Long. 54°25’ W., 582 fathoms, temp. 3°3; I female. 
5. Ascomyzon tenerum n. sp. 
(Pl. I, figs. 3 a—3 k.) 
Female. — Cephalothorax (fig. 3 a) conspicuously less broad than in the preceding form, and more 
slender than in any European species. Head slightly broader than long; the three thoracic segments with 
the lateral margins convex and the postero-lateral corners rounded; third segment well developed, some- 
what long. — Genital segment (fig. 3 b) moderately narrow, somewhat longer than broad and broadest in 
front of the genital apertures. Second abdominal segment somewhat broader than long, a little longer than 
third segment; caudal rami as broad as long, with the outer margin a little shorter than the terminal segment. 
Antennulee (fig. 3 c) 20-jointed; the ten distal joints slender, eleventh to seventeenth joint consider- 
ably to very much longer than broad and rather unequal in length; eleventh joint rather long; from eleventh 
to fourteenth the joints decrease, and from the last-named to seventeenth they increase considerably in length, 
so that the seventeenth joint, which is four and a half times as long as thick, is as long as thirteenth and four- 
teenth together or as the eighteenth to twentieth together. — Antenne (fig. 3c) long and very slender; 
terminal spine somewhat or considerably longer than the two distal joints together. — Sipho (fig. 3 c) reaches 
beyond the insertion of first legs or beyond that of second legs, and it is shaped nearly as in A. latwm figured 
by Sars. — Maxillule (fig. 3 c) with the inner branch long and slender, and three among its four terminal 
setee nearly half as long again as the branch; outer branch very small and thin, only a little more than one- 
fifth as long as the inner, while its longest terminal seta reaches about to the end of the inner branch. — 
Maxille (fig. 3c) slender; dactylus with claw not half as long again as the proximal part. — Maxillipeds 
(fig. 3 c) long and very slender; claw more than half as long again as the dactylus. — Fifth legs (fig. 3 e) very 
oblong, only with the 2 terminal sete. 
Length I mm. 
Male. — As usual more slender than the female and differing in the antennule, the maxillipeds, 
and the abdominal segments. — Genital segment (fig. 3 k) from scarcely as broad as to slightly broader than 
long, with a small tooth on each postero-lateral angle. Last segment somewhat broader than long, slightly 
shorter than the two preceding segments together. Caudal rami a little longer than broad, and their outer 
margin distinctly shorter than that of the last segment. 
