NO. 9 MARINE INVERTEBRATES, ALASKA — MacGINITIE 169 



(Owens) occurred at Eluitkak Pass and at depths of from lo to 

 150 feet. The legs and thorax of this species are large in comparison 

 with the abdomen. This hermit apparently prefers shells of Natica 

 and Polinices for its short abdomen, or perhaps these shells were 

 the most abundant form in the size appropriate for the small abdomen. 

 The hermit never "wore" a shell large enough to withdraw into, and 

 the large thorax and legs were always exposed. Unlike most of its 

 relatives, it was usually not difficult to remove it from its shell, and 

 it did not evidence the usual distress shown by hermit crabs without 

 a shell. Specimens of this hermit were frequently brought up with- 

 out any shells at all, but the shells were no doubt lost during dredging. 

 Since plenty of empty shells of Natica and Polinices were available, 

 the fact that large hermits of this species often wore shells so tiny 

 that only the very tips of their abdomens were inserted in the shells 

 is sufficient evidence of their lack of concern about having their abdo- 

 mens housed. The carapace and legs of this species were a reddish, 

 iridescent blue. The eggs were dark blue, but they turned to orange 

 in preservative. 



Pagurus trigonocheirus (Stimpson) was much more abundant in 

 hauls than splcndescens. It occurred at Eluitkak Pass and from no 

 to 522 feet. Although a few were taken on muddy bottom at 80 feet, 

 this hermit appears to prefer stony substrate or transitional areas 

 between the muddy and stony bottom. Again, this may be more a 

 matter of living where suitable housing is available rather than a 

 preference as to bottom, for the shells of Ncptunea and Buccinum, 

 which this hermit inhabited, were found largely on stony bottom. In 

 contrast with splcndescens, trigonocheirus often uses shells that are 

 much larger than necessary. Time and materials did not permit the 

 preservation of more than a few of the specimens brought up in hauls. 

 P. trigonocheirus is host to two parasitic cirripeds at Point Barrow : 

 Clistosaccus paguri and Peltogaster depressiis (see "Cirripedia"). 

 Two large males had specimens of Spirorhis on their telsons and 

 uropods, and a large female had a small colony of the octocoral 

 Eunephthya ritbiformis growing on its carapace. 



The most abundant of the true crabs was Hyas coarctatus alutaceus 

 Brandt, which was present in nearly every haul from 80 to 477 feet. 

 Males (carapaces up to 75 mm. long) were larger than the females 

 (carapaces up to 49 mm.). Ovigerous females with freshly deposited 

 eggs were taken from the first of August to the middle of October. 

 This species has a purplish-red carapace, and the legs are reddish 

 brown above and light beneath. The lower two-thirds of the outer 

 face of the hand is white and the lower half of the inner face is white 

 with reddish-brown specks. 



