1 66 THE CRUSTACEA 



Sometimes, but not always, it is absent from the last pair also in 

 Anaspides. In the males of both genera the first two j^airs have 

 the endopodites modified as copulatory organs. In the first pair 

 of Anaspides the endopodite is a thick lobe, curved inwards and 

 having a group of retinacula on a short process (perhaps a vestigial 

 appendix interna) near the distal end of its inner edge. The endo- 

 podite of the second pair is composed of two segments, the first 

 elongated, bearing some spines and a group of retinacula near the 

 distal end, and the second curved and spoon-shaped. In the 

 natural position these appendages are turned forwards, the endo- 

 podites of the second pair lying ■within the trough formed hy the 

 apposition of those of the first pair, and between the latter and the 

 sternal surface of the thorax. 



The uropods in Anaspides are large, with lamellar rami, fringed 

 with spines and setae, and form, with the telson, a tail-fan of the 

 usual type. The exopodite is crossed by an incomplete suture or 

 line of articulation near the distal end. In Koonunga the protopo- 

 dite is relatively longer and the rami are not so broad, so that the 

 fan-like arrangement is not quite so typical. The exopodite is 

 undivided. 



As regards the internal anatomy, our information is as yet very 

 restricted, and refers only to Anaspides. 



Alimentary System. — The masticatory stomach appears to be of 

 very simple type, its armature consisting of longitudinal chitinous 

 ridges beset with setae. The extent of the mid-gut has not been 

 ascertained. The hepatic caeca are numerous, very long slender 

 tubes. There are two median dorsal caeca — one in the region of 

 the first and the other in the fifth abdominal somite. 



Circulatory System. — The heart is a long tube extending 

 through a great part of the length of the body. The number of 

 the ostia has not been ascertained. There is stated to be an 

 unpaired descending artery originating from the under-surface of 

 the heart between the last two thoracic somites. 



Excretory System. — On each side of the head, posterior to the 

 mandibles, is a glandular mass of considerable size, showing in 

 sections a convoluted tubular structure. No duct has yet been 

 traced from it, but its position suggests that it may be the maxillary 

 gland. 



Sense- Organs. — The paired eyes of Anaspides are set on short 

 movable peduncles ; those of Koonunga are very small and are 

 sessile on the sides of the head. 



In both genera a saccular invagination of the integument, sup- 

 posed to be an otocyst (or statocyst), is found in the basal segment 

 of the antennular peduncle. It opens by a small slit on the dorsal 

 surface of the segment. Internally, on the upper side, is a row of 

 peculiarly modified setae. Each is divided into two segments, the 



