338 
BULLETIN OF THE BUREAU OF FISHERIES 
and 6 a. m., corroborating his view that T. catharina comes to the surface most often 
by night. 
As a rule, Tomopteris has been represented in our hauls by large adults or 
medium-sized specimens 15 to 40 millimeters long, with from 15 to 21 parapods, 
and Doctor Huntsman informs me that he has invariably found this to be the case 
in the Bay of Fundv. But during our August cruise of 1913 we took a considerable 
number of its young in the northern and western parts of the gulf, including speci- 
mens as small as 4 to 8 millimeters in length, with only 6 to 8 parapods (but identi- 
fiable as this species by the tail, already visible, and by the number and location of 
the rosette organs), at about the stage figured by Apstein (1900, pi. 10, fig. 2), as 
follows : 
Locality 
Station 
Number 
of speci- 
mens 
Stage of development 
German Bank 
10095 
0) 
1 
6 millimeters upward, 8 to 12 parapods. 
6 millimeters, 12 parapods. 
8 and 11 parapods. 
10 millimeters, 12and 14 parapods. 
Do. 
Northeast corner off Grand Manan 
10097 
North of Cashes Ledge 
10089 
2 
Near Mount Desert island 
10099 
2 
Off Penobscot Bay 
10101 
2 
Eastern basin 
10093 
1 
5.5 millimeters, 13 parapods. 
7 millimeters, 11 parapods. 
4 millimeters upward, 6 parapods and 
upward. 
6 millimeters upward, 8 to 14 parapods. 
Off Penobscot Bay 
10091 
1 
Oil Cape Elizabeth 
10103 
(>) 
(>) 
15 to 18 miles southeast from Chatham, Cape Cod 
1 Several. 
Judging from the early stage in development represented by these specimens, 
it appears that T. catharina reproduced itself in some numbers in the Gulf of Maine 
during the summer in question, proving that it is actually endemic there and not 
restricted as a breeder to more northern seas. Although young specimens have 
not been detected in our tow nettings before or since at any season (evidence that 
it would be quite exceptional for Tomoptens to breed in any abundance within the 
gulf), what little reproduction does take place there may be enough to maintain 
the rather sparse stock of this worm. 
Of course, this does not negative the possibility that more or less immigration 
takes place into the gulf from the north (p 339) ; but the distribution of T. catharina 
in eastern Canadian waters, as outlined by Huntsman (1921), suggests rather that 
the Gulf of Maine colony is to some extent isolated and separated from the more 
abundant stock of this worm in Newfoundland waters and in the region of the Lau- 
rentian Channel by a considerable gap, for it was taken at only one station inside 
the continental edge along Nova Scotia by the Canadian fisheries expedition of 
1915. Our scanty data point to an early summer breeding season, which agrees 
with Southern’s (1911) discovery — based on the occurrence of females with eggs 
as well as of young — that it breeds from May until August in Irish waters. 
Relation to temperature and salinity. — The highest temperature in which w 
have positively established the presence of T. catharina m the Gulf of Maine is 14.44° 
(surface haul, Station 10245, August 12, 1914), and the great majority of captures 
have been from water colder than 8°. At the other extreme it has been taken in 
