340 BULLETIN 129, UNITED STATES NATIONAL MUSEUM 



Measurements. — ^Largest male, holotype, median length of carapace 

 16.3, length from middle of posterior margin to tip of horns 20.8, 

 width (approx.) without spines 12.8, with spines 14 mm. Female, 

 ovigerous (55121), length of carapace from middle of posterior margin 

 to tip of horns 12.3 mm. 



Range. — Chile: Juan Fernandez (Lenz). 

 Mcbterial examined. — Juan Fernandez Island ; 

 U. S. C. S. S. Hassler; 12 males, 6 females 

 (2048, M. C. Z.); 1 male, 1 female (55121, 

 U.S. N. M.). 



Remarlcs. — This species is closely allied to 

 P. peronii and some of its differences might 

 be attributed to growth change. On the other 

 hand, the preorbital spine would be unlikely 

 to disappear altogether, or one of the large 

 branchial spines to develop where there was 

 no trace of one in the young. Considering 

 the great distance between their habitats, the 

 ^ _ „ ' difference in the size of mature specimens 



Fig. 108.— Paramitheax back- . ... 



sTROMi, MALE (55121), MEDIAN (maturc specimeus of peromi are from 55 to 

 LENGTH OF CARAPACE 16.3 MM., gQ nim. lu length, of Uckstromi from 12 to 20 



MAXILLIPED il<>i • •in 



mm.), and the fact that some spines m odck- 

 stromi are absent in peronii, while the reverse is true of other spines, 

 it seems reasonable to consider the two forms distinct. P. hdcJcstromi 

 has a more oblong, less ovate carapace than peronii, increased by the 

 more outstanding rostral and preorbital spines. All the spines except 

 the postorbital, hepatic, anterior branchial and outer antennal, are 

 slenderer and sharper than in the older species. Add to this, the 

 more elaborate ornamentation of arm and wrist in hdckstromi and the 

 absence of a large tooth from the dactyl, while one is present in 

 peronii. 



Genus TEMNONOTUS A. Milne Edwards 



Temnonotus A. Milne Edwards, Crust. R^g. Mex., 1875, p. 82; type, T. 

 granulosus A. Milne Edwards. 



Carapace swollen, slightly pyriform; margins rounded. Cardiac 

 region almost surrounded by a deep trench. Rostrum formed of 2 

 short horns in the middle and a preorbital spine on either side. The 

 orbital border has a superior fissure; eyes large and retractile into a 

 deep lateral fossette. Inner antennae large, the interantennular 

 partition prolonged in ' a spine. Basal article of outer antennae 

 wide at base and narrowed at extremity, and separated from lower 

 orbital margin of the carapace by an emargination; it is concealed 

 by the front, but the mobile part of the antennae is visible beside 

 the rostral horns. Merus of outer maxillipeds dilated at outer 



