344 EDWARD S. MORSE ON 



natural flexures (50 : 17) . The mouth is slightly dilated ; the oesophagus is long, straight, 

 cylindrical, and marked by encircling muscular fibres, and makes an abrupt turn just 

 before it enters the stomach which is slightly dilated. A strong peristaltic action of the 

 oesophagus continues some hours after its separation from the body. The stomach and 

 intestine run downward parallel to the oesophagus ; the intestine continues with a slight 

 turn forward until near the end where it turns upward and dorsally, and terminates in a 

 blunt point. There is no buUjous enlargement at the end, as figured by Hancock, though 

 in his specimen the end of the intestine might have been packed with excrementitious 

 matter. The intestine is cylindrical and retains the same diameter throughout, tapering 

 only at the end, and is brownish in color. The stomach has smooth walls. The first part 

 of the intestine presents a glandular appearance ; halfway to the end of the intestine a 

 few spiral markings are seen, and at the end a few longitudinal markings occur. The 

 " heart of Hancock " is a testicular knob lying back on the stomach and narrowing at its 

 point of attachment. 



Stomachal Glands. 



One of the marked characteristics of all Brachiopoda is the stomachal glands, usually 

 known as the liver. These appear, at an early stage, as simple, wide diverticula of the 

 stomach. At the outset these folds present the color which is ever after retained. These 

 simple folds contract and expand independently of each other, and through life the same 

 contractility is manifested by the individual coeca making up the mass. The young stages 

 of Discinisca, Terebratulina, and Hemithyris present these features alike. The simple 

 fold splits into separate branches and these subdivide again and again until there is formed 

 a great tuft-like mass of branching coeca varying in certain features in each genus, being 

 long and tu))u]ar in Hemithyris, brandling like a stag's horn in Terebratulina, and 

 assuming the shape of blunt clusters in the Lingididae. The coeca, furthermore, seem as 

 fully charged with diatoms and other food material as the stomach itself. 



Similar diverticula of the digestive tract are seen among the worms, and their func- 

 tion has been interpreted as hepatic. Gegenbaur ('78) throws out a word of warning in 

 his " Elements," wherein he says, " The glandular organs connecting with the mid-gut are 

 ordinarily regarded as hepatic, or as the ' liver '. We must be careful not to attribute 

 anything more than the value of a convenient distinction to these names." It is well 

 known that these glandular conditions are found in the Polyzoa, Rotatoria, and other 

 groups ; tlie contents of tlie cells are different in color and therefore, says Gegenbaur, 

 they might rightly be considered as secreting appendages. Dr. Arnold Lang ('96) calls 

 attention to the fact that the mid-gut diverticula are universal in the Malacostraca, and 



