1918 Bovard and Osterud; on Emhryological Material 135 



MoUuscoidea 



Terebratella transversa Sowerby. Common in shore collecting and 

 trawling. It yields numerous translucent eggs ; but no motile sperms have 

 been found. 



Platy helmint hes 



Leptoplana sp. Fairly common under stones on Turn Rock, Minne- 

 sota Reef and adjacent shores at low tide. The animals will deposit eggs 

 in dishes or on submerged slides. Egg patches contain a single layer of 

 eggs, one to each capsule, embedded in a yellow matrix. The heavy yolk 

 hinders the study of later stages. The eggs are very hardy and withstand 

 stagnation conditions for some time. Their development is slow. 



Cerebratulus monigomeryi Coe. No ripe eggs were obtained, but many 

 pilidium larvae were found in tow during the latter part of the season. 



Arthropoda 



Epialtus productus Randall. Abundant on eelgrass, on kelps, and on 

 piles under the docks ; common to a depth of at least 40 fathoms. Indi- 

 viduals carrying eggs were found frequently thruout the summer session. 



Telmessus cheiragonus Rathbun. Occasionally found at Brown Is- 

 land, Arglye Lagoon, Turn Island, Madrona Point to Minnesota Reef. 

 Females carrying eggs were observed during the summer of 1917 and 

 early in July of 1918. 



Hyas lyratus Dana. Abundant forms with wide distribution. Com- 

 mon in trawling. Females carrying eggs, also early stages of develop- 

 ment, were observed during the summers of 1917 and 1918. 



Hemigrapus nudus (Dana) Rathbun. Abundant crabs along shore. 

 It is the common purple shore-crab. Females carrying eggs are commonly 

 found early in the session. 



Upogebia pugetensis Dana. Common in sand-beaches along with 

 Nereis. Specimens with eggs found occasionally; the eggs hatch out as 

 zoea. Their period extends at least from June to August. 



Upogebia sp. This was found carrying eggs during the summer 

 session. 



Caprella sp. A very abundant amphipod found on the eelgrass gen- 

 erally, and in large numbers among the hydroid colonies on the eelgrass 

 at False Bay. The eggs are carried in brood sacs from which the young 

 are liberated as zoea. Larvae were well advanced by July 7, 1918. 



Balanus aquilla Pilsbry. Common. A very large barnacle brought 

 up in the trawl. It yields embryos in various stages. The larvae are lib- 

 erated as nauplii. The eggs in early stages of development were found 

 on July 15, 1918. 



