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Palatable (Batesian) mimics of unprofitable models could use behavioral mimicry to compensate for the ease with which they can be visually discriminated, or to augment an already close morphological resemblance. We evaluated these contrasting predictions by assaying the behavior of 57 field-caught species of mimetic hover flies (Diptera: Syrphidae), and quantifying their morphological similarity to a range of potential hymenopteran models. A purpose-built phylogeny for the hover flies was used to control for potential lack of independence due to shared evolutionary history. Those hover fly species that engage in behavioral mimicry (mock stinging, leg waving, wing wagging) were all large wasp mimics within the genera Spilomyia and Temnostoma. While the behavioral mimics assayed were good morphological mimics, not all good mimics were behavioral mimics. Therefore, while the behaviors may have evolved to augment good morphological mimicry, they have not been selected in all hover fly species.

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Deep-sea nudibranchs (Mollusca: Gastropoda: Heterobranchia) have rarely been reported from eastern Canada. Here we describe range extensions for two species found in the northwest Atlantic Ocean. Tritonia newfoundlandica Valdés, Murillo, McCarthy & Yedinak, 2017 was originally collected on the Flemish Cap off Newfoundland, Canada, and Doridoxa ingolfiana Bergh, 1899 was originally found off western Greenland with further records in Iceland, northern Norway, and southeastern Canada. We extend the northern range of T. newfoundlandica 1067 km along the eastern coast of North America and add occurrences of D. ingolfiana in the Labrador Sea, bridging a 2044 km gap between previous records in Greenland and southern Newfoundland. The latter species thus exhibits a continuous distribution from Svalbard, the Faroe Islands, Greenland, down to the southern tip of the Grand Banks in eastern Canada. Tritonia newfoundlandica was collected in its known depth range, whereas the depth distribution of D. ingolfiana was extended by 30 m to a maximum depth of 1375 m. Both species were collected with numerous nephtheid corals, suggesting that there may be a functional relationship, where the nudibranchs find refuge or food on them.

The earthquake of 3 June 1956 on the Arctic margin of Canada, north­west of Borden Island, has been briefly studied during a reappraisal of instru­mental data of some Canadian earthquakes. The revised parameters are: lat­itude 79.83°N±0.20°, longitude 116.99°W±l.0°, crustal depth (18±18 km), H = 05h 19m 26.6s U.T., and magnitude mb 5.7, Ms 5.4. The epicentre is unlikely to be more accurate than ±20 km. This is the second largest earthquake known from the Arctic margin of Canada.