80 W. C. M'INTOSH ON VALENCINIA ARMANDI. 



the ovaries are filled with large ova, and stretch from a little below the nerve-trunks on 

 each side upward to the dorsal region of the great longitudinal muscular coat, and 

 encroach considerably on the alimentary chamber behind the proboscidian sheath. 



EXPLANATION OP PLATE. 

 Plate XVI. 



The following letters are used to designate the respective parts throughout the series ;■ — 



a. Cutis. 



b. Basis-layer of the cutaneous system. 



c. Circular muscular coat of the body. 



d. Longitudinal muscular layer of the body. 

 a o. Proboscidian sheath. 



d' '. Special layer of separated longitudinal muscles anteriorly. 



h. Ganglia. 



j. (Esophageal region of the digestive system. 



f. Alimentary canal proper. 



n. Lateral nerves. 



r. Median raphe. 



v. Great longitudinal vascular trunks. 



w. Mouth. 



A. Proboscis. 



Fig. 1. Transverse (vertical) section near the tip of the snout of Valencinia Armandi: v, v, vascular 

 meshes by which the great trunks unite, x 210 diam. 



Fi°-. 2. Transverse section of the snout behind the former. The two horizontal bands of fibres (e and e') 

 have now attained considerable development ; and numerous vertical fibres pass from their sur- 

 faces to the circumference : ao, canal for the proboscis in the snout. Numerous longitudinal 

 muscular bundles (d) occur along the inner faces of the horizontal bands and in the forks of the 

 vertical series, x 210 diam. 



Fig. 3. Transverse (and somewhat flattened) section just in front of the mouth, through the ganglia (h). 

 The separated series of longitudinal muscles {d') are very conspicuous in this region, though a 

 process of the mouth (w) interrupts the circuit inferiorly. The proboscidian sheath (ao) is some- 

 what flattened out. The two accessory vascular meshes, s, s, are probably homologous with 

 those found in a similar situation in the typical Anopla ; m, powerful transverse muscular band, 

 separating the chief from the accessory vascular channels ; ml ', ring of circular and longitudinal 

 fibres surrounding the united area of the proboscidian and the vascular systems. In this pre- 

 paration the proboscidian sheath is differentiated from the general investment of the united area 

 very distinctly, x 90 diam. 



Fig. 4. Similar section through the mouth. The separated series of longitudinal muscles (d') are still 

 very evident. They form a considerable mass on each side of the mouth inferiorly. The basis- 

 layer (6) of the cutaneous system is greatly developed in this region. The proboscidian sheath 

 is wholly independent of the digestive system, a special band of longitudinal fibres (z) besides 

 the sheath proper and other tissues intervening. The commencement of the great longitudinal 



