666 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [26] 



largest of these had U-shaped tubes, 28 to 31 inches in length and over 

 an inch in diameter in the middle. In each tube there was usually a 

 crab (Pinnijca chcrtopterana St.), associated with the worm. These tubes 

 show, very beautifully, the way in which their size is continually in- 

 creased by the occupant, which is incapable of emerging from it. The 

 worm makes longer or shorter slits in the parchment-like tube, wher- 

 ever it is to be enlarged (probably using for this purpose the sharp, stiff, 

 lance-like setfE of the anterior segments), and after spreading the tube, 

 from within, to the desired extent, it closes up the opening by means of 

 a fusiform patch (like a " gore" or " gusset"), of the same material as 

 the original tube, but differing slightly in color or luster, so that when 

 the tube is cut open these neat patches show very distinctly on its inner 

 surfiice. 



From the sands of i^'aushon, at Hadley Harbor, our party also pro- 

 cured several living examples of an European shell, TclUmya (or Mon- 

 tacuta) ferrvginosa, not before found on our coast. It was associated, 

 at low-water mark, with living specimens of 31. hidentata and another 

 species of the family, Kelliadae, Corbula contracta, etc. Drawings were 

 made of the animals of all these by Mr. Emerton. 



Of Gastropod veligers, about twenty species were taken in the sur- 

 face nets. Some of these occurred in vast numbers, but I have not yet 

 been able to identify more than half of the species. Among those rec- 

 ognized are AnacMs avara, Astyris lunata, Triforis nigrocincta, etc. One 

 of the largest and most interesting was that of a Natica. This had the 

 velum divided into four long, narrow lobes, beautifully marked with 

 brown at the tips. Many of these were kept till they lost the velum 

 and developed the characteristic foot of Natica. The species is uncer- 

 tain. 



In a region that has been so thoroughly dredged in past years as 

 Vineyard Sound, it was not to be expected that many new forms would 

 be found, unless among the more minute species, or in those groups not 

 hitherto studied on our coast. Yet one new Planarian,* of large size 

 and with conspicuous colors, was taken, as well as various undescribed 

 Khabdocoela and Annelida. 



* Stylochopsis zebra V., sp. nov. — Body broad-eliptical, rather thick, or somewhat 

 swollen. Tentacles small, near the front end, bearing several small ocelli ; a cluster 

 of small dorsal eyes in front of tentacles ; minute, marginal ocelli, along the front 

 edges. Color brown and pale yellow or whitish, in narrow, alternating, transverse 

 stripes, which run directly across in the middle, but become more and more V"8haped 

 as they approach each end. Length about 20'n°, breadth 1*2""°. Great Harbor, shore ; 

 off Menemsha, 10 to 1'2 fathoms, September 6. 



