226 STALK-EYED CRUSTACEA. 
Fansenomysis and Ceratomysis, being furnished with exopods and internal 
meral lobes. 
Petalophthalmus, Scolophthalmus, Hansenomysis, and Ceratomysis, form a 
natural group of genera characterized by the development of seven pairs 
of incubatory lamelle in the female (the anterior pair sometimes rudimen- 
tary), the absence of an exopod from the maxillipeds, the outgrowth of a 
large, porrect lobe from the inner margin of the merus of the gnathopods, 
and the imperfect development of the carapace, which leaves the last two 
segments of the cephalo-thorax free. This group is connected with the more 
normal genera of Myside through the genus Loereomysis, in which the incu- 
batory pouch is likewise composed of seven pairs of lamelle, but the maxil- 
lipeds are furnished with an exopod, the gnathopods lack the internal meral 
lobe, and the carapace covers all the thoracic segments. The maxillipeds 
have an internal meral lobe in Petalophthalmus, Ceratomysis, and Boreomysis ; 
the gnathopoda are furnished with an exopod in all the genera excepting 
Petalophthalmus.  Petalophthalmus differs from all the other genera here men- 
tioned in the absence of an exopod from the gnathopods and in the enormous 
development of the mandibular palps. In the great size of the antennu- 
lar peduncle as compared with the second antennse, Scolophthalmus exhibits 
special affinity with Petalophthalmus. 
Scolophthalmus lucifugus Fax. 
Plate LV., Fig. 1-1. 
Bull. Mus. Comp. Zodl., XXIV. 219, 1893- 
Rostrum long, acute; antero-lateral margins of carapace oblique, armed 
with two spines, one behind the external side of the antennule, the other 
at the antero-inferior angle; posterior lateral wings short and rounded. 
Abdominal segments smooth and subcylindrical, sixth segment nearly as 
long as the two antecedent segments combined. 
Length, 42 mm. 
Station 3400. 1322 fathoms. 1 fem. 
