liev. A. M. Norman on Crustacea Cumacea 
55 
2. Diastylis cornuta (Boeck). 
P1S53. Cuma bispinosa, Stimpson, Marine Invertebrata of Grand Mu nan,, 
p. 39. 
1860. Cuma cornuta, A. Boeck, Vidensk. Selsk. Forhandl. p. 190. 
1864. Diastylis bispinosa, G. O. Sars, Om Cumacea, p. 89. 
1865. Diastylis bicornis, Bate, Ann. & Mag. Nat. Hist. ser. 3, vol. xv. 
p. 84, pi. i. fig. 2. 
1868. Diastylis bispinosa, Norman, Brit. Assoc. Report, 1868 (1869), 
p. 270. 
I am not satisfied that this is the Cuma bispinosa of Stimp- 
son, though it is the species which has been known by that 
name among European carcinologists. I am not aware that 
the form for which I here adopt Boeck’s name has been re¬ 
corded from the American coast; and specimens of a New- 
England Diastylis are before me which seem to agree more 
nearly with Stimpson’s brief description. 
Sars says that the male of this Diastylis has a spineless 
carapace; but I have males which closely agree in the spiny 
armature of the carapace with the females,* these are not, 
however, fully developed, inasmuch as the lower antennm 
and uropods have not attained their plumose characters. It is 
hardly likely, however, that the subsequent exuviation, in 
which a change in degree of development would take place in 
these organs, would result also in so great a change in kind as 
from a strongly spinous to a smooth carapace. Fully developed 
males of Diastylis are scarce—that is, males in which the an¬ 
tennas have attained their excessive length and the verticillately 
ciliated peduncle, and the abdominal feet have their swimming 
setae on the peduncles. Such males I have seen of only a few 
species that I could assign to their females; they are more 
commonly taken in the tow-net than at the bottom, where, 
from their great activity, they probably generally succeed 
in escaping the dredge. 
Diastylis cornuta was taken in the 1 Porcupine ’ Expedi¬ 
tion, 1869, in Lough Foyle, in 15 fathoms, and at Station 21, 
lat. 55° 40'N., long. 12° 46' W., in 1476 fathoms. 
3. Diastylis insignis , G. O. Sars. 
1871 .Diastylis insiynis, G. O. Sars, CEfvers. af Kongl. Vet.-Akad. 
Forhandl. p. 76 j id. Beskrivelse af de paa Fregatten Josephines 
expedition fundne Cumaceer, Kongl. Svenska Vetensk.-Akad. Handl. 
ix. p. 34, pi. xiv. figs. 68-71. 
A strongly marked and beautiful species, descibed by Sars 
from the ‘ Josephine ’ Expedition, having been taken on a 
muddy bottom in 550 fathoms off the coast of Portugal. A 
single specimen was dredged in the 1869 1 Porcupine ’ Expe- 
