FAUNA OF THE ALEUTIAN ISLANDS AND ALASKA PENINSULA 397 



caecum decipiens — this worm also was taken from the stomach of 

 an adult hair seal on Khwostof Island. External parasites of the 

 cod included a copepod, Lepeophtheirus parviventris, an isopod, 

 Rocinela belliceps, and a leech, Platybdella quacbnoculata. 



Stomach contents of cod were examined from time to time, 

 partly out of curiosity and partly to recover specimens of in- 

 vertebrates for the general collection. Common items in the diet 

 included large amphipods (often half a pint or more in a single 

 stomach) , shrimp, octopus or squid beaks, sea urchins, snails, 

 clams, crabs, and many small fishes. Near Chuginadak Island, on 

 August 21, the head of an adult cormorant Phlacrocorax sp. was 

 found in a cod stomach. Off Ogliuga Island, on August 12, the 

 entire body, considerably softened, of a parakeet auklet (Cy- 

 clorrhynchus psittacula) was recovered (Scheffer 1943). 



Gasterosteus aculeatus aculeatus, the three-spined stickleback, 

 was taken on three islands in fresh-water pools. G. a. microcephalus 

 was taken on four islands, also in fresh-water pools or streams. 

 Both races of aculeatus may be found in both salt and fresh water, 

 but the resident salt-water form is more heavily plated and is 

 given the subspecific name aculeatus, while the resident fresh- 

 water form is given the name microcephalus. In fresh water, all 

 but four or five plates near the head are eventually lost. 



In some places, as on Kavalga Island, sticklebacks occur in ponds 

 on plateaus isolated from the sea and now inaccessible to fish. It 

 is our opinion that the fish gained access to such ponds before the 

 outlet streams became steep. 



In several cases, sticklebacks were noted heavily infested with 



Figure 18. — Red sculpin, Hemilepidotus hemilepidotus; color: red and brown. 



Kagamil Island, August 29, 1938. 



