MUSEUM OF COMPARATIVE ZOÓLOGY. 243 
characters do not appear of sufficient importance to warrant a separation of the 
genera; for the segmentation is sometimes obscurely indicated in Colossendeis, 
and the size of the abdomen cannot have more than a specific significance. 
Unfortunately, I have been unable to obtain Jarzynsky's paper, and I cannot 
ascertain its exact date, Rhopalorhynchus was described in 1873, and probably 
has priority. In the want of certain evidenee, however, I have preferred to 
follow Sars in adopting the former name, Miers has recently redescribed the 
genus (Annals and Magazine of Natural History, January, 1881) under the 
name Anomorhynchus. If Rhopalorhynchus and Colossendeis are distinct, Miers's 
genus is identical with the latter, with which his description agrees in every 
particular. 
The species described by Jarzynsky as C. borealis is stated by Sars to be 
identical with Sabine's Phoxichilus proboscideus, described many years ago. If 
Sabine's description is trustworthy, his species is widely different from any 
of the forms described below. 
Colossendeis angusta, Sars. 
Prodromus Deseriptionis Crustaceorum et Pyenogonidarum, que in Expeditione 
Norvegica Anno 1876, observavit G. O. Sars. < Archiv for Mathematik og 
Naturvidenskab, Andet Bind, 1877, pp. 268, 269 (368, 369 by error). 
Plate III. Figs, 8, 13. 
SPECIMENS EXAMINED. 
Stat. Locality. Depth. No. 
338 AN. Lat. 889 18' 40”, W. Long. 78? 18^ 10” 922 fathoms. 1 sp. 
308 s 41? 24' 45”, y 66°. 85’ 307” 1242 ue 2 sp. 
305 Pn dis uds ไช้ Hn 65° 51! 25" Sloe. ss 2 sp. 
This beautiful species has hitherto been known from three specimens dredged 
by Sars off the west coast of Norway, N. Lat. 63° 10.2’, W. Long. 4? 59.6', 417 
fathoms. Its range is thus extended nearly 25 degrees of latitude southwards, 
and from 417 down to 1242 fathoms, — a striking instance of the southward 
extension of arctic forms in deep water. 
The specimens differ slightly from Sars's description, but the disagreement is 
probably within the limits of variation. It may be convenient to describe 
some of the characters of the specimens. 
The body is very trimly built, with nearly parallel sides, and with only very 
obscure indications of articulations between the segments, Lateral processes 
short, separated by nearly equal intervals about as wide as the processes, Ab- 
domen about one third the length of the body (without the rostrum). Ocu- 
liferous segment very short indeed, suddenly widening just in front of the first 
pair of lateral processes, and there forming the widest ‘portion of the body. The 
oculiferous tubercle is variable. Sars described it as “ spinam longam et acumi- 
natam formans . . . ., pigmento et lentibus omnino destituta.” The spine is 
scarcely “long and acuminate " in our specimens, though forming a very acute 
