96 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
of the families is represented by only a few species, I am unable to 
attempt improvements in the classification of any of them. In a pre- 
vious paper — Isopoden, Cumaceen und Stomatopoden der Plankton- 
Expedition (Ergebnisse der Plankton-Expedition der Humboldt-Stiftung, 
Bd. II. G. c) —I have proposed a partly new arrangement of the Iso- 
poda, with observations on some of the families, and to this treatise 
the reader must be referred for several particulars. I have thought it 
useful to illustrate all the species rather fully, and to describe them 
in some detail, taking into consideration the best representations in the 
literature, yet altering and adding where it seemed advisable. 
ASELLOTA. 
Of this large tribe only two species were secured. Both belong to the 
Munnopside G. O. Sars, a family rather badly limited, and both must be 
referred to the genus Lurycope G. O. Sars. Unfortunately, the material is 
rather scanty and all the specimens are much mutilated, yet I am able to draw 
attention to a point of significance, namely, that the genus with the limits 
still adopted presents startling differences in the structure and shape of the 
mandibles of some of the species. In the two species here described the 
mandibles possess distally a cutting portion, behind this a “ lacinia mobilis ” 1 
with a row of setee on each mandible and a strong “ cuspis lacinia” on the 
left one, and farther backward a well developed molar process. In the small 
Norwegian species the mandibles seem to be of similar structure,? but in the 
large Eurycope gigantea G. O. Sars they are very different. In this species 
each mandible has a very long oblique edge on the inner side, the molar process 
is very short and badly defined, no lacinia mobilis is found, etc. It may be 
added that the two pairs of jaws also present differences from those in the 
species to be described here. (The mouth organs of Eurycope gigantea were 
first described by G. O. Sars in the Norwegian North-Atlantic Expedition, 
Zoöl., Crustacea, Vol. I. pp. 132, 133, Plate XI. Fig.910-14, and shortly after- 
wards by the present author in his account of the Crustacea in Dijmphna- 
Togtets zool.-bot. Udbytte, 1877, pp- 199-201, Tab. XX. Fig. 3c-3g.) It is 
interesting to observe that great differences in the structure and armature of 
1 This and the following term are set forth and explained in my paper: Ciro- 
lanidæ et Fam. nonn. prop. Musei Haun. (K. Danske Vidensk. Selsk. Skrifter, 6 
Række, naturv.- math. Afdeling, V. pp. 239-426, Tab. I-X.) 
2 At my request, Prof. G. O. Sars very kindly sent me the proof-sheets containing 
the account of the Munnopside, in his new leading work on the Isopoda. He has 
divided the family into two families, etc., but he still maintains the genus Lurycope 
in its old and very wide extension, yet remarking that some of the species estab- 
lished by Beddard “ought perhaps more properly to be separated as types of 
nearly allied genera.” 
