1904.] ASELLOTA-GROUP OF CRUSTACEANS. 319 



XJropoda considerably less than half as long as the abdominal 

 shield ; the endopod somewhat longei- than the exopod. 



Length of a female with marsvipium 5-2 mm. ; Has well gives 

 the length | inch. 



Occurrence. According to Haswell this species has been captured 

 on the south-eastern coast of Australia : Port Jackson, Port 

 Stephens, Griffiths' Point (Victoria). Of a specimen in the 

 British Museum (from Griffiths' Point) I have figured the abdomen 

 from below ; two specimens (from Port Jackson), belonging to 

 the Museum in Dundee, have kindly been forwarded me, and my 

 three other figures of this species were taken from one of these 

 specimens, an almost full-grown female. 



Remarks. This species is easily distinguished from all following 

 forms, S. fractum Ohilt. excepted, by the shape of the head and 

 basal joint of antennae, together with the joints of first thoracic 

 legs. Its differences from S. fractum are mentioned in the 

 following description of this species. 



2. Stbnetrium FRACTUM Chilton. 



1887. Stenetrium fractum Chilton, Transact, and Proc. New 

 Zealand Institute, 1883, vol. xvi, p. 249, pi. xviii. 

 figs. 3 a-f. 



Chilton described and figured a single specimen, the body of 

 which had been " much crushed." Unfortunately, he says nothing 

 as to the shape of the head ; but judging from the antennae and 

 the shape of abdomen, I think that the species must be related 

 to S. armatum Hasw. Most of the characters given below have 

 been selected among his statements, other characters have been 

 derived from his figures*. 



Antennulse. — " First joint of the peduncle large, as broad as 

 long ; second equal in length to the first, but more slender ; third 

 rather longer than the second, ... flagellum about half as long 

 again as the third joint of peduncle, consisting of about five 

 joints ...." 



Antennae have the basal joint " produced acutely at its extero- 

 distal angle " ; according to fig. 3 h the process does not reach the 

 end of second joint. 



First thoracic legs. — Fourth joint much expanded above and its 

 upper corner produced into a rather long triangular process, which 

 seems to be a little shorter and thicker than in S. armatum. 

 Fifth joint shaped about as in the last-named species. Hand very 

 deep, about |- as long as deep, thus proportionately considerably 

 deeper than in the female of aS'. arinatimi ; upper margin as in 

 that species ; lower margin seems to be a little convex ; the angle 

 between this margin and the palmar edge almost 120°; palmar 

 margin straight, armed with thick setse pectinate along their 

 upper margin and a spine of very moderate length at the lower 

 angle. Seventh joint and claw as in the female of S. armatum. 



* My friend Dr. W. T. Caiman has kindly sent me a copy of Chilton's description 

 and tracings of his figures. 



