320 EDWARD S. MORSE ON 



while the cirri are directed inward and forward, their tips coming just at the junction 

 of these tubes (40: 1^) . The cirri are strongly ciliated and their vigorous motions 

 induce the currents above described. 



The pecuhar alignment of the lateral setae in Glottidia and L. lepidula will be under- 

 stood when it is seen that the shells taper slightly from the posterior lateral bunches of 

 setae, which are quite prominent toward the anterior end, while the lateral setae vary in 

 length, being quite short posteriorly and becoming gradually longer anteriorly, so that 

 when the dorsal and ventral shells are closed, or when the animal is in the act of crawl- 

 ing, it will be noticed that lines drawn along the tips of the lateral setae on each side 

 would be parallel ; now when the shells gape anteriorly and the setae meet across the 

 gradually increasing space between the shells, the tips of the setae touch along the whole 

 side (40: 15) , the increasing length of the setae anteriorly balancing, so to speak, the 

 gradual widening made by the parted shells. 



On alarm, caused by the jarring of the vessel in which it is contained, or the inter- 

 posing of a hand between it and the light, the animal snaps below the sand like a flash. 

 The opening left in the sand is in shape Uke a transverse section of the body, with the 

 sand piled up in a wide, shallow ridge around the opening (40 : lO) . 



The animal, as might be supposed from an examination of the powerful oblique 

 muscles, possesses considerable strength ; this strength may be shown by placing upon it 

 a heavy weight, such as the shell of a large Donax when in a short time this weight is 

 flung off by the oscillations of the dorsal valve. 



Lingula anatina. A large green Lingula, presumably L. anatina, was collected in 

 numbers at the mouth of the Takahashi River, Higo, Japan, a river that empties into the 

 Shimabara Gulf, the waters of which are so shoal that small steamers cannot approach 

 within two miles of the shore at this point. The Lingulae were found in a gravelly and 

 muddy deposit just beyond low tide. They were collected by drawing the fingers 

 through the mud in rake-like fashion. The end of the peduncle was encased in a rough 

 tube of mud an inch or more in length ; in no instance was it attached to any solid 

 substance. The blood was pinkish lake in color and, with the admixture of mucus, quite 

 thick and dark, discoloring the water and staining the fingers in dissection. The auditory 

 vesicles, to be described later, were plainly visible in the smaller specimens where the 

 shells were not so opaque. The dorsal shell oscillates quite as freely and smugs as far to 

 the right and left as in Glottidia pyramidata, though moving less vigorousl}'. The 

 general behavior of the animal and the rich brown markings of the pallium and brachia 

 were not unlike the smaller species with diaphanous shells ; the ventral shell was rigidly 

 fixed and held by the stout peduncle, which was quite firm and inelastic near the shell ; 

 the lateral setae swung back and forth, but not with that vigorous action seen in the 

 smaller species. 



