HALIPORUS DORIS. 191 
H. obliqurostris is described as having small exopods on all the legs, and 
these organs are represented on the posterior pair of legs of the female 
H. equals on Plate XL, Fig. 1”. In HZ. nereus there are rudimentary exo- 
pods attached to all the legs, as well as to the third maxillipeds. 
Hymenopeneus Smith,* appears to be equivalent to Haliporus Bate. 
Haliporus doris Fax. 
Plate XLIX., Fig. 1-1. 
Bull. Mus. Comp. Zodl., XXIV. 214, 1893. 
This is a larger and more robust species than HW. nereus, with the ros- 
trum more upturned. In all other respects, excepting the structure of the 
sexual organs on the sternum of the female (the male has not been seen), 
the two forms agree so closely that one description would serve for both. 
The character of the parts above referred to is so constant in the same 
species among the Crustacea, that, in the light of our present knowledge, 
the form here treated of must be considered a distinct species. The tuber- 
cular processes of the third pair of legs, together with the sternal tuber- 
cles immediately behind them, are very like the same structures in ZZ. nereus. 
But here the likeness ends. Betwixt the fourth pair of legs there is a trans- 
verse diaphragm consisting of a median tongue, concave on its anterior face, 
and with its lower free edge entire, supported on each side by a strong, 
blunt, triangular process, of equal height with the median tongue-like plate. 
Between the bases of the legs of the fifth pair, in place of the low longitudinal 
median ridge seen in //. xereus, there is in this species a large, setiferous, tri- 
gonal tooth or tubercle, acute at the tip, equalling in height the transverse 
partition on the sternum of the antecedent segment. The posterior median 
angle of this tooth abuts against the low transverse ridge that forms the 
posterior limit of the last thoracic sternum. 
The differences between these structures in the two species H. nereus and 
H. doris will be easily understood by reference to the figures on Plate 
XLVIIT. and Plate XLIX. 
The third maxillipeds and all the legs carry rudimentary exopods, as in 
LT. nereus. 
Length, 104 mm. ; rostrum, 10 mm.; whole carapace, 42 mm. 
* Bull. Mus. Comp. Zodl., X. 91, 1882. 
