130 DR. G. HERBERT FOWLER ON THE [ Feb. 3, 
that this family takes its origin very near to the root of the 
Decapodan stem, and that it has far closer affinities with the 
latter than with the Myside. In Wyctiphanes’ and Huphausia *, 
and possibly in other genera also, the youngest Calyptopis-larvee 
show seven spines on each side of the telson; unlike all other 
Schizopoda, so far as is known, except perhaps Lophogaster, they 
are thus in absolute accord with the ‘“ urspriingliche Borstenzahl 
7+7” which Mayer attributes to the primitive Macruran and 
Brachyuran. In Huphausia, Nyctiphanes, Thysanopoda, and 
Nematoscelis according to Sars (op. cit.), and in Thysanoessa, 
the number is increased at later stages by a median terminal 
spine, which, like the others, is jointed to the telson. Accepting 
Mayer’s enumeration of the spines from the middle line outwards, 
and styling the median azygos spine of the EKuphausiide as 0,— 
spines 7 are found in the adult Thysanoessa about one-third of 
the length of the telson from the root; spines 6 at about two- 
thirds of its length from the root; spines 5 are lost; spines 4 
persist as the large lateral jointed spines near the end of the adult 
telson *; and spines 3, 2, 1, 0 disappear altogether in the course 
of development. On page 131, I have illustrated four stages in 
this reduction omitted by Sars, of which fig. 15 does not quite 
bear out his description: these show the disappearance of the 
median spine 0, and the commencement of a new wnjointed 
growth of the telson backwards, to form the lanceolate tip of the 
adult. The character of the telson and the presence of this 
median spine will apparently form a good criterion for the 
separation of Kuphausidan larvee (at stages later than the Meta- 
nauplius) from other Schizopodan and from Decapodan larvee. 
The earliest Calyptopis-larvee captured by the ‘ Research’ 
resembled closely those figured by Sars (op. cit.) for other genera, 
except for the facts that the carapace was much more globular 
anteriorly and was devoid of spines or processes. 
NYcTIPHANES NORVEGICA M. Sars. 
This form was captured on only six occasions. Although a 
North Atlantic type, it is not an essentially Arctic type like 
Thysanoessa longicaudata : it is of constant occurrence in certain 
localities on our own coasts, and has been recorded from as far 
south as Portugal. The various records of its occurrence are cited 
by Canon Norman *, but unfortunately the size of the individuals 
and the depth from which they were derived are only rarely noted. 
I am informed by Sir John Murray that, in his experience, large 
adult specimens are taken only in deep water. 
1 G. O. Sars: Chall. Rep. Zool., xiii. Schizopoda, pl. xxvii. fig. 6. 
2 C, Claus: Untersuch. Crustaceen-Systems, pl. i. fig. 2, Wien, 1876, 4to. 
3 With regard to these, Boas (op. cit. p. 623, note 5) has suggested that they may 
be homologous with the long caudal appendages of Nebalia and many Phyllopods. 
This possibility is rendered considerably more remote by their being merely two 
persistent spines out of a series which is not represented in the forms cited by him. 
4 A.M. Norman: Ann. Mag. Nat. Hist. (6) ix. pp. 459-460 (1892). 
