462 CRUSTACEA MALACOSTKACA. 



of dots on the dorsal surface of the head, of unknown function. 

 The stomach is situated far forward in the thorax and there are 

 some 18 slender " hepatic " diverticula. The heart is a long tube, 

 tapering at either end, and the wide part lies between the middle 

 and the posterior end of the thorax. The excretory organ has 

 not been identified, nor has the position of the generative orifices 

 been satisfactorily determined. The alleged position of the male 

 orifice on the first abdominal segment, and that of the female 

 between the 7th and 8th thoracic, would be exceptional among 

 the Malacostraca, and in neither sex was the duct followed to its 

 opening. Eggs 1 mm. in diameter have been found in the oviduct, 

 yet no trace of brood lamellae has been found, and it is probable, 

 therefore, that a series of free larval stages occurs in development.* 



A group of small Crustacea, Palaeocaris, Gampsonyx and 

 Acanthotelson, from the Carboniferous and Permian rocks of 

 the Old and the New Worlds, have been recognized by palaeon- 

 tologists as occupying an isolated position among the Malacos- 

 traca, and have been classed by Packard in the group Syncarida. 

 Caiman pointed out that they " agree with each other and with 

 Anaspides, and together with it stand apart from all other 

 Crustacea whatsoever, in combining with the absence of a 

 carapace, the presence of distinctly podophthalmate characters 

 in antennules, antennae, and tail-fan " f Palaeocaris appears 

 to have had biramous thoracic legs, but it is not clear that this 

 was the case in the other genera, nor are the epipodial plates 

 preserved in the fossil forms, hence these features so characteristic 

 of Anaspides cannot at present be included in the definition of 

 the Syncarida as a group, f 



Genus Anaspides Thomson. Tasmania. 



* Sinca this was written Anaspides has been investigated afresh by Mr. 

 G. Smith. The author has learnt from Mr. Smith that he has found the 

 free-swimming young in the form of the adult of so small a size that he 

 has no doubt that they are hatched essentially in this condition. It 

 appears therefore that Anaspides, like Astacus and other freshwater 

 forms, undergoes no considerable metamorphosis. 



| Loc. cit., p. 796. The Malacostraca with stalked eyes have been 

 classed in a group the Podophthalmata, in contrast with the Edrio- 

 phthalmata, or sessile-eyed forms ; an arrangement which is now generally 

 abandoned. 



| Koonunga cursor has recently been described by O. A. Sayce (Victorian 

 Naturalist, vol. 24, No. 7 (Nov. 1907). It is in. long and lives in fresh 

 water pools, near Melbourne, Victoria. The thoracic legs are like those 

 of Anaspides, but the eyes are sessile, and there is no scale to the second 

 antenna. 



