MUSEUM OF COMPARATIVE ZOOLOGY. 243 



characters do not appear of sufficient importance to warrant a separation of the 

 genera ; for the segmentation is sometimes obscurely indicated in C'olossendeis, 

 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. Rhopulorhynchus was described in 1873, and probably 

 has priority. In the want of certain evidence, however, I have preferred to 

 follow Sars in adopting the former name. Mie^s has recently redescribed the 

 genus (Annals and Magazine of Natural History, January, 1881) under the 

 name Anomorhynchus. If Rhopalorhynchus and C'olossendeis are distinct, ^liers's 

 genus is identical with the latter, with which his description agrees in every 

 particular. 



The species described by Jarzynsky as C. horealis 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 Descriptionis Crustaceorum et Pycnogonidaruin, quse in Expeditione 

 Norvegica Anno 1876, observavit G. 0. Sars. < Archiv for Mathematik eg 

 Naturvidenskab, Andet Bind, 1877, pp. 268, 269 (368, 369 by error). 



Plate in. Figs. 8, 13. 



SPECIMENS EXAMINED. 

 Stat. Locality. 



338 N. Lat. 38° 18' 40", W. Long. 73" 18' 10" 

 308 " 41° 24' 45", " 65° 35' 30'' 



305 " 41° 33' 15", " 65° 51' 25" 



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 



