contains a number of ova fertile and unfertile. The unfertile 
ej2;gs serve as food for the larvae developed from the fertile 
ones and there is a certain amount of competition between the 
larvae in the capsule which results in the most vigorous larvae 
getting more food and making a larger growth than the more 
weakly coinhabitants of the capsule. Thus at the time of 
leaving the capsule and coming into the outer world, it some- 
times happens that there will be perceptible differences between 
the individuals issuing from a single capsule, not only in actual 
size but in the length of the coil of whorls and the size and 
compactness of the larval apex." 
In the beam trawl only a small percentage of the larger 
shells that get into the net actually reach the deck of the vessel, 
most of them going through the coarse-meshed net before reach- 
ing the pocket; thus their relative abundance is only proble- 
matical. As it was, the number of Chrysodomus decemcostatus 
was about double that of Buccinum undatum. In all, some 56 
specimens were collected, including some of remarkably large 
size. One Chrysodomus measured 5.5 inches with about 0.25 
of an inch broken away, making its total length about 147 
mm., with a diameter of 90 mm. Gould gives the length as 
'S inches, and Tryon 2.5 to 4 inches. The number of ribs varies 
somewhat, about one half having ten (counting the subsutural 
rib), one fourth eleven, and the other fourth nine ribs. 
The specimens of Buccinum collected were also unusually 
large for New England waters, one with apex broken measuring 
nearly 5 inches or about 125 mm, in length, with a diameter of 
2.5 inches. Gould gives its length as usually 3 inches, and 
Tryon 3.25 inches. The specimens also varied greatly in form 
and sculpture, the spire in many being unusually high, with 
the longitudinal undulations wanting on the body whorl. 
EXPLANATION OF PLATE. 
Fig. 1. Egg-oapsules of the Common Whelk {Buccimnn undatum). 
Fig. 2. Egg-capsules of the Ten-ribbed Whelk {Chrysodomus decem- 
costnt}i,'i). 
