PHYTO-PLANKTON OF BAY OF FUNDY 105 
SESSIONAL PAPER No. 38a 
As found in New Brunswick waters the genus Ditylum (dis, two, and tyle, a 
swelling) is usually in the form of a lengthened quadrate cylinder, due to the great 
length of its zone or girdle, the terminal valves being somewhat puckered or con- 
stricted, with slight but conspicuous bristles at the angles bordering a circle or fringe 
ot very delicate and short bristles, from the centre of which springs a single long 
and stout spine. The sculpture of the valve is radio-punctate, the rays being delicate 
and grouped around the base of the central spine. The arcolation, so marked in 
Triceratium, is entirely wanting. Though usually triangular, specimens have been 
observed in which triangular, quadrate, and pentagonal valves have been found, 
enclosed in the same connecting membrane, which is very imperfectly silicified. In 
the writer’s opinion the forms are much more nearly related to Rhizosolenia and 
Corethron, than to either Triceratiwm or Biddulphia. They are often found in groups, 
of which the individuals may be attached either laterally or by the ends, on the 
sagittal plane. As to distributional and seasonal variations, the representatives 
of the genus Ditylwm have been found in the bay of Fundy, near St. John, in 
February, and at St. Andrews in April, but only rarely. They were abundant in 
Deadman’s harbour, August 10, and especially abundant in ‘St. Andrews harbour, 
and off Grand Manan, in October. They were also observed during this latter month 
at the mouth of the St. Croix river, but rarely. 
Fragillaria—This genus, though usually to be found in plankton collections 
elsewhere, is not common in the region under review. This species represented appears 
to be mainly Fr. capucina and Fr. pacifica (?). 
Grammataphora.—tThe species Gr. marina and Gr. serpentina are both found in 
the bay of Fundy and Passamaquoddy bay, but not very generally. They were both 
found rather abundantly and forming long chains in the waters about West Quoddy 
Head on the 28th of June; at Eastport, August 1 and St. Martins, also at L’Etang 
harbour, August 10. None were observed in the ‘‘Prince” collections, made in 
September and October. 
Hyalodiscus.—This genus, as represented by the species H. subtilis, is occasion- 
ally met with in the plankton, but not in sufficient numbers to be made the basis of 
comparative statements. It is found but rarely in Passamaquoddy bay. 
_ Isthmia.—Only a few specimens of this genius, including both J. nervosa and I. 
enervis, have been observed in the summer plankton about Campo Bello; but not in 
Passamaquoddy bay. 
Melostra—No genus is more widely or more abundantly met with than this, its 
rabit of forming long chains, some times including thirty or more frustules, making 
it quite conspicuous. The most common species is M. nummuloides, though lM. 
varians and M. Borerti and M. Jerghensii are by no means rare. They have been 
found at various stations jn the bay of Fundy and also about Passamaquoddy bay. 
M. subflexilis was found at St. John and St. Andrews, in February and March, the 
others almost everywhere during the summer months. In the “ Prince” collection 
M. subflexilis was obtained between St. John and Digby on the 21st of September, 
and quite abundantly. 
Navicula.—Specimens of this genus, which includes a very large number of 
species, are found in nearly all collections, but the majority of the latter are littoral 
rather than pelagic or planktonic. Of those occurring in the plankton one of the 
most common and widely distributed is N. didymo, which has been found during the 
summer months at many points along the coast between Grand Manan and St. 
Martins. N. distans and N. Smithi (including Nelliptica) are also of common 
occurrence; but none have yet been recorded from winter collections. They are 
common in Passamaquoddy bay, in July and August. 
