CYSTISOMATIDAE 



271 



parkinsoni, Stebb. i mand. spine ; ? ventr. spines ; antennae moderately far apart, longer than 

 head. 



magnum (Wolt.). i mand. spine; 5 pairs ventr. spines; antennae far apart "(Woltereck's 

 figure), shorter than head. 



longipes (Bov.). 2 mand. spines ; (5-) 6 pairs ventr. spines ; antennae far apart, about length 



of head ('Thor ', in type broken off short). 

 bovallii (Wolt.). 2 mand. spines; ? ventr. spines; antennae more or less equal to head. 



(Possibly = longipes.) 



latipes (Steph.). 2 mand. spines ; 5-6 pairs ventr. spines ; antennae close together, longer than 

 head; 2nd (1st free) joint of peraeopod 7 markedly pyriform. 



africanum, Brnrd. 3 mand. spines ; 6 pairs ventr. spines ; antennae far apart, length ?. 



Species insufficiently described: loveni, neptunus, "spitiosum". 



Cystisomids appear to be inhabitants of the deeper layers, as they are only captured 

 when the apparatus is sunk to considerable depths (except the earliest known specimens, 

 Woltereck, 1904, p. 562). But the exact depth is known only for a very few specimens. 

 The ' Challenger' used no closing nets; we are uncertain about the Valdivia (Woltereck, 

 1904, p. 561) and the Gauss specimens. The 'Thor' (Stephensen, 1918, p. 70) obtained 

 the majority (nine) of her specimens at 1000-2000 m., two at 2000-3000 m. and one at 

 over 4000 m. 



The 'Discovery' only obtained two specimens in closing nets, viz. at Stations 216 

 and 219 in 750-500 and 750-535 m. 



As regards life-history various larval forms have been described (Woltereck, 1904; 

 Senna, 1904; Stephensen, 1918; Spandl, 1927) and Woltereck, 1904, p. 526, inclines 

 to the view that the adults rise to higher levels at certain seasons ; but our data are yet 

 far too meagre to determine whether there is any particular breeding season. 



It may be interesting to note that fully adult females are recorded during the following 

 months (latitude approximate) : 



The collection of the ' Thor ' was made during the months of February (one larva) and 

 May, June and September, but no adult female was taken. 



Our knowledge of the geographical distribution of the genus has been considerably 

 extended by the Discovery captures. The most southerly records hitherto known were: 



1 This is the only ? that Woltereck explicitly states (and figures) to be "ripe", i.e. with enlarged 6th 

 joint to peraeopod 5. 



