FISHERY BULLETIN: VOL. 82, NO. 2 



3 and 4; posterior margin of carapace 

 convex 4 



4a. Carapace length 1.2-1.4 mm; antennal 

 flagellum and scale (including distal 

 spine) about same length; antennal scale 



< 5 times as long as wide 



Dermaturus mandtii 



4b. Carapace length 1.4-1.7 mm; antennal 

 flagellum longer than antennal scale 

 (including distal spine); antennal scale 



about 9 times as long as wide 



Paralithodes brevipes 



5a. Carapace with middorsal posterior spine 



Rhinolithodes wosnessenskii 



5b. Carapace without middorsal posterior 



spine 6 



6a. Antennal scale with s 6 markedly short 

 (<l/2 scale width), lightly plumose 

 setae Hapalogaster mertensii 



6b. Antennal scale with ^ 6 long ( > 1/2 scale 



width), heavily plumose setae 7 



7a. Posterolateral spines of carapace project 

 somewhat laterally; telson has ^11 pairs 

 of spines (excluding minute hair); longest 

 (third) pair of telsonic spines fused to 

 telson Lithodes aequispina 



7b. Posterolateral spines of carapace do not 

 project laterally; telson has ^ 8 pairs of 

 spines (excluding minute hair); longest 

 (third) pair of telsonic spines jointed with 

 telson 8 



8a. Spines on posterior margins of abdominal 

 somites 2-5 markedly long and tips blunt; 

 posterolateral spine on abdominal somite 



5 blunt and sinuate 



Placetron wosnessenskii 



8b. Spines on posterior margins of abdom- 

 inal somites 2-5 typically short and tips 

 pointed; posterolateral spine on abdom- 

 inal somite 5 pointed and not sinuate .... 9 



9a. Telsonic spines 8 + 8 (excluding minute 



hair) Paralithodes platypus 



9b. Telsonic spines 7 + 7 (excluding minute 



hair) Paralithodes camtschatica 



Described Lithodid Glaucothoe of 



the Northern North Pacific Ocean. 



Glaucothoe of Hapalogaster grebnitzkii, 



Placetron wosnessenskii, and Rhinolithodes 



wosnessenskii have not been described. 



la. Dorsal surface of carapace without 

 spines 2 



322 



lb. Dorsal surface of carapace with spines 



4 



2a. Carapace triangular 



Cryptolithodes typicus 



2b. Carapace rectangular 3 



3a. Lateral margin of carapace with teeth 

 in branchial region but not in hepatic 

 region Hapalogaster mertensii 



3b. Lateral margin of carapace with teeth 



in branchial and hepatic regions 



Dermaturus mandtii 



4a. Tips of anterolateral spines of rostral 

 complex spinulose; most, if not all, 

 spines on dorsal surface of carapace 

 bifid Lithodes aequispina 



4b. Tips of anterolateral spines of rostral 

 complex styliform or bifid; most, if not 

 all, spines on dorsal surface of carapace 

 styliform 5 



5a. Carapace with 15 pairs of spines on 



dorsal surface Paralithodes platypus 



5b. Carapace with < 15 pairs of spines on 



dorsal surface 6 



6a. Carapace with 14 pairs of spines on 



dorsal surface . . Paralithodes camtschatica 



6b. Carapace with 13 pairs of spines on 



dorsal surface Paralithodes brevipes 



Paralithodes brevipes may have three stages; 

 thus, Table 2 may not always be appropriate for 

 distinguishing the stages of this species. Kurata 

 (1956) reared and described the larvae of P. 

 brevipes from ovigerous females collected in Jap- 

 anese waters. In Kurata's description, P. brevipes 

 has three zoeal stages instead of the four that 

 characterize the genus, and Stage III zoeae cor- 

 respond morphologically to Stage IV zoeae of the 

 genus. Makarov (1967), however, found four zoeal 

 stages of P. brevipes, including a Stage III zoea, 

 in plankton of the west Kamchatkan coast that 

 correspond morphologically to Stage III zoeae 

 of the genus. Kurata's zoeae may have skipped 

 Stage III of the genus because growing conditions 

 in the laboratory were especially favorable (Mak- 

 arov 1967). 



Only Stage I zoeae of Placetron wosnessenskii, 

 and Stages I and II zoeae of Rhinolithodes wos- 

 nessenskii have been described (this report). 

 Because these zoeal stages are morphologically 

 typical of lithodid species with four zoeal stages, 

 P. wosnessenskii and R. wosnessenskii like- 

 ly have the four zoeal stages characterized in 

 Table 2. 



