132 
Walter M. Tattersall. 
apical setae were piumose. This was a clerica! error for "not piu- 
mose". 
Illig has noted for this species, as well as for most of the other 
Mysidae which he has described from the Valdivia collections, the 
presence of a small slender papilla on the inner ventral surface of 
the eye and has further noted in the species he calls Eiichaetomera 
limbata^ that in the male this papilla is much longer than in the 
female. The same sexual difference is to be noted in the present 
species, the papilla in the male extending for quite half its length 
beyond the cornea of the eye and being, moreover, very slender. 
At the same time, I cannot but think that Illig has attached too 
much importance to the Omission of any mention of such papillae 
from the diagnoses of various species by earlier authors, more 
especially of species of Euchaetomera. The eyes of examples of 
the latter genus are very delicate and fragile and seldom retain 
their form in preserved specimens so that it is often a matter of 
great difficulty to make out their exact shape and structure. For 
instance, in the present material of Euchaetomeropsis merolepis, 3 of 
the 5 specimens bave either no eyes at ali or the eyes are reduced 
to irrecognisable pulp. A fourth specimen has one eye more or lesa in 
good order, the other, absolutely fragmentary while only one of the 
specimens has the two eyes in a tolerably fair state of preservation. 
When it is further remembered that the papilla is situated on the 
ventral face of the eye and is usually small, it will be readily 
understood that its existence is very liable to be overlooked unless 
specially sought for, and even then it may be lost sight of, in the 
general mass of setae from the antennal scales and antennular pe- 
duncles. Under the circumstances, therefore, I cannot resist the Sug- 
gestion that the species named by Illig (1906) Euchaetomera glyphi- 
diophthalmica and E. limhata will prove eventually to be synonymous 
respectively with E. tennis and E. typica, species described by Sars 
from the Challenger collections, for it seems to me that Illig has 
been chiefly led to regard them as new, from their possessing ocu- 
lar papillae and from the absence of any mention of such papillae 
in Sars' diagnoses. 
E. merolepis is an interesting addition to the fauna of the 
Mediterranean. It is a bathypelagic species, captured, so far as 
present records show, in water from 900 — 2500 m (500 to 1200 fa- 
thoms). Illig's specimens were caught in the Indian ocean. 
