280 EDWARD S. MORSE. 



ing food as described in S. velum. Alternate movements of the 

 side of the siphonal opening were observed as in S. velum. The 

 anterior aspect of the creature was much the same, the two 

 median dorsal tubercles, one behind the other, and the anterior 

 edge of the mantle bearing papillae. The posterior aspect was 

 quite different from S. velum and resembled more closely S. 

 togata of the Mediterranean as figured by Stempell. The 

 resemblances are seen in the large size of the median dorsal 

 tubercle, the few small tentacles in pairs, succeeded by a pair of 

 very long tentacles, then a number of very minute tentacles 

 bordering the upper edges of the siphonal opening followed by a 

 number of tentacles increasing in size to the lower portion of the 

 opening (Fig. 21). All of these tentacles were retractile, the 

 upper series appearing like round tubercles when contracted- 

 The longer tentacles surrounding the orifice were in constant 

 action, a bcnding-in movement as if grasping. 



In the collection of fifteen specimens of S. borealis the indi- 

 viduals varied in length from 9 mm. to 83 mm. Omitting the 

 smallest specimen the others were easily arranged in four distinct 

 series of sizes as follows : 



ist Series. 2d Series. 3d Series. Full Grown. 



24 mm. 39 57 73 



29 mm. 40 59 77 



31 mm. 44 77 



31 mm. 78 



83 



Twenty-eight specimens of S. velum from Sandwich were in 

 the same way readily grouped in series. One measured 7 mm. 

 in length, 6 averaged 10 mm., 8 averaged 12 mm., 5 averaged 13 

 mm., 6 averaged 15 mm. and 3 averaged 19 mm. From this 

 one might infer that Solenomya is not an annual. 



In conclusion I wish to say that this brief examination of the 

 external features of S. borealis has convinced me that my sup- 

 position that the Annisquam individual might be the young of 

 S. borealis is incorrect. Furthermore that a study of a more 

 advanced specimen of S. velum, at Woods Hole showed a nearer 

 approach to the Annisquam specimen. I have never seen a 

 minute specimen of 6*. velum and Professor Drew informs me that 

 he has never found one with eggs. The protoconch of Solenomya 



