t 



THE MARINE POLYZOA OF CANSO, NOVA SCOTIA 77 

 SESSIONAL PAPER No. 22a 



obliquely upward. Generally only one pair of spines is present, and these are erect and 

 situated near the top of the orifice. 



FAMILY : CRIBRILINID^ 



Crihrilina punctata (Hassall) ? — I found two specimens, the identity of the first of 

 which I am not sure. The first specimen was found encrusting a shell of Litorina 

 which was inhabited by a hermit crab. The boundaries of the cells of the zoarium are 

 not distinct ; the whole front of the zooecium is perforated with punctures of large size, 

 giving it a reticulated appearance ; the peristome is not greatly thickened on the lower 

 edge, and bears no mucro ; it has two spines on the upper margin that are directed in- 

 wards. The avicularia are generally absent, but an occasional one is seen on the edge 

 of the peristome. The ooecia are largei, covered with punctures, and contain ova of a 

 beautiful pink colour. The second specimen was found on a stone at low-water mark. 

 The two lateral avicularia are present on almost every cell. The spines on the peris- 

 tome are rather irregular in number, some cells having none, some two. The lower 

 border of the peristome is very slightly thickened, but the mucro is absent. 



Cribrilina annulata (Fabricius). — Several very small patches were found on a stone 

 between tide-marks, and a small patch 5 mm. in diameter, together with several other 

 small patches, consisting of from one to three cells, was obtained from the frond of 

 Rhodymenia palmata dredged in 20 fathoms, near the entrance to 'Canso harbour. All 

 the specimens are of a pure white colour. In the larger patch on Rhodymenia the mar- 

 ginal zooecia retain a pair of transparent spots laterally, also two above the orifice. 



family: MYRIOZOIDiE. 



8chizoporeUa sinuosa (Busk). — A very old, encrusting mass was found on a stone 

 taken by the trawler Active. The individuals can be distinguished by the naked eye. 

 The orifice is orbicular, produced into an angle below. The wall is punctured, especi- 

 ally near the edge, where the punctures are large. 



Schizoporella hyalina (Linnaeus). — This species is very common about Canso. I 

 have found it on Laminaria longicruris, Fucus vesiculosus, Ascophyllum nodosum and 

 a red alga. In all cases it was found in very shallow water or just below tide-mark. 

 The lateral denticles vary a good deal in size, sometimes being very conspicuous when 

 the ventral sinus is deep, or very small when the ventral sinus is shallow. 



FAMILYS ESCHARID^. 



Lepralia pallasiana (Moll). — A colony was found on a stone taken from under a 

 wharf. There is no umbo, avicularia nor ooecia present; the reticulation is very pro- 

 nounced and beautiful, the margin of the peristome is not greatly raised and its lower 

 margin is more strongly curved than is indicated in Hincks' drawings. 



Lepralia pertusa (Esper). — Specimens were found encrusting an ascidian dredged ' 

 by the trawler Active. As I am not at all sure of the identity of this specimen, I 

 shall give my notes in full. July ±d : Zoarium encrusting of a white colour in sev- 

 eral small patches. Zocecia are very distinct, separated by raised lines, and form radi- 

 ating rows ; they are mostly rectangular, a few having a pointed base ; a very distinct 

 line of large pores at each lateral edge border the dividing, raised lines; these pores 

 are separated by ridges passing inward radially for a short distance ; the orifice is trans- 

 versely elliptical with a distinct sinus on the lower side; just below the lower lip is 

 a raised, conical or tubular structure with an opening circular above, but prolonged 

 into an angle below; this structure does not come out straight but runs obliquely to- 

 ward the orifice, no avicularia are present. Every feature is very distinct. July 27 : 

 Another specimen taken which is younger. It has an orange appearance and the walls 



