THE NAUTILUS. 11.1 



through the water on the way home. It is by no means easy work 

 hauling the dredge, leaning over the side of the scow to wash the 

 contents of the sieves, and we have narrow escapes from sea-sickness 

 on rough days. 



Outside the islands, in deep water, we have dredged the Denta- 

 linm striolatum, valves of the Panomya norvegica, Mya truncata and 

 Liocyma flnctuosa, and alive the Menestho albula, Admete couthouyi, 

 Puncturella noachina, Lepeta caeca, Modiolaria nigra, Modiolaria dis- 

 cors and Modiolaria corrugata, also the Cardium islandicum. 



On arriving home, the material collected is spread in the sieves to 

 dry in the sun, and we find it difficult to wait until it is dry enough 

 to bring into the work room. It is only by careful picking over that 

 the smaller species are obtained and it is in this way that we get good 

 series of the Rissoidie. The Rissoa, or rather Oingnla castanea, 

 Rissoella eburnea, Turbonella nivea, Turritella acicula, and Turritella 

 erosa, Molleria costulata, Retusa gouldii and Retusa petemn's, and the 

 Diaphana debilis. 



Many live specimens are put into shallow dishes, and under the 

 microscope it is most interesting to watch the Margaritas, Belas, 

 Lunatias and the active Yoldias moving about. 



A day's dredging thus means a good deal of work, and after all 

 comes the labelling and putting in the cabinet, last but not least of 

 a day's dredging. 



OBSERVATIONS ON THE GENUS QUADRULA. 



BY L. S. FRIERSON. 



In his admirable Synopsis of the Naiades, Mr. Chas. T. Simpson 

 says (page 766), that although he had examined thousands of ani- 

 mals of the plicata group of Quadntla, he had never seen but a 

 single one having eggs in the gills, and that other students had found 

 them equally barren. In NAUTILUS (vol. xv, no. 4, p. 39), H. von 

 Ihering speaks of the specimen of Q. heros Say, examined by Lea, and 

 of the specimen seen by Sterki, and he seems to be rather doubtful 

 whether Quadrula (of this group at all events) always carry eggs in 

 all four gills. My observations of late have been singularly lucky in 

 this respect and will, I think, settle this point. The h'rst specimen 



