346 DEPARTMENT OF THE NAVAL 8ERTICE 



8 GEORGE V, A. 1918 



Distrihution. — Bay of Fundy, low water to 40 fathoms (Verrill) ; Le Have bank, 

 45 fathoms (Smith and Harger) ; Orphan bank (Whiteaves) ; St. Andrews (Stafford) ; 

 Barrington passage, shallow water, Canso, low water (Eraser) ; Grand Manan (A. 

 Agassiz) ; at various points from the south end of Grand Manan to the head of Passa- 

 maqoddy bay, off Brier island. 2'2 fathoms. 



Since Agassiz described specimens from the New England coast and the Bay of 

 Fundy as belonging to a new species Clytia hicophora, few authors have considered 

 the species distinct from Clytia johnstoni. Nutting, in his Woods Hole paper, and 

 later in his monograph, treats it so, but in his later paper he has included his earlier 

 species, Clytia grayi, with Clytia johnstoni. He states that Clytia hicophora is a 

 much more delicate and smaller species, the hydrothecse of C. johnstoni being on 

 the average twice as long and wide as those of C. hicophora," and later, " The diag- 

 nostic marks of Clytia hicophora are the comparatively small size of the hydrothecse, 

 the presence of a simple instead of a complex diaphragm, and the tenuity of the hydro- 

 thecal walls." He speaks of the diaphrag-m of C. Johnston as being " strong, thicker 

 than usual, and the basal chamber well shown." The hydrotheca of C. johnstoni is 

 said to have 16 teeth, that of C. hicophora, 12 to 14. 



In the material under consideration there were specimens of this species, or of 

 these species, from 18 localities, ranging from the southern end of Grand Manan 

 island, through Passamaquoddy bay and up the St. Croix river, the very region from 

 which Agassiz obtained some of his specimens. There were also some from St. Mary 

 bay on the Nova Scotia side of the Bay of Fundy. For comparison I have specimens 

 from Canso, N.S., and Woods Hole, Mass., together with specimens of Clytia john- 

 stoni from the coast of Devon, England, obtained from the British museum. 



First considering the size of the hydrothecse, Nutting gives no measurements, 

 the figures are not all drawn to the same scale of magnification and the scale is not 

 given in any instance, hence it is impossible to be sure what size he considers suitable 

 for each species. It is possible to find in one locality a variation as great as he gives 

 as the distinction and sometimes not far from that much variation in the one colony. 

 The average size of the English specimens is much the same as that of the Canso 

 and Woods Hole specimens and scarcely any of those found in the bay of Fundy 

 were smaller than these, the majority being larger and some of them being much 

 larger. Those from St. Mary bay were larger and most of those from Passamaquoddy 

 bay and vicinity are also; those well in from the direct waters of the bay of Fundy 

 are, in general, larger than those more nearly out in the open. Thus, those from the 

 vicinity of Deer island and at the mouth of the St. Croix river are larger on the 

 average than those obtained from Grand Manan, the Wolves and Bliss island. 



Some measurements will show this : The length of the hydrothecse in the Devon, 

 Canso, and Woods Hole specimens, varies from 0-5 to 0-65mm., St. Mary bay, 0-55 to 

 0-65, Grand Manan, 0-45 to 0-8, Bliss island, 0-5 to 0-75, Deer island, 0-6 to 1-0, 

 mouth of the St. Croix river, 0-75 to 1-05. The length varies from 1-5 to 2 times the 

 breadth. The largest specimens answer well to the type on which Nutting based the 

 species, C. grayi. It is scarcely probable that Nutting described C. hicophora from 

 specimens with hydrothecse half the length of the smallest of these. It is more likely 

 that there is a variation in size in the British specimens as there is in the bay of 

 Fundy specimens and possibly Nutting has examined some of the larger ones while 

 I have some of the smaller ones. 



With regard to the thickness of the diaphragm, it is quite natural that the larger 

 specimens have thicker diaphragms than the smaller but I find that when the smaller 

 ones are examined under higher magnification, so that they appear equal in size to 

 the larger, there is no constant difference in the appearance of the diaphragm. This 

 is borne out by Nutting's figures. In fig. 3, pi. XII, where the drawing of the hydro- 

 theca of C. hicophora is shown as large as that of C. johnstoni in the preceding plate, 

 the diaphragm is shown even more plainly than in the drawing of C. johnstoni. The 

 same is true in the case of the basal chamber. 



