94 DRIOMENIA PACIFICA. 



the anterior pedal gland. From external view this proboscis is not visible, 

 the ventral furrow appearing to extend to the atrial chamber. The mouth leads 

 into a slender tube, with irregular longitudinal folds, and becoming gradually 

 larger as it courses dorsally it opens into the stomach-intestine. About midway 

 it connects with two short ducts from the salivary glands wedged between the 

 stomach-intestine and the anterior pedal gland in the general position represented 

 (Plate 38, fig. 1). Each salivary gland cell is pyriform, slightly vacuolated 

 with distinct compact nucleus and unites with the main outlet by means of a 

 very slender ductule. 



The anterior coecum and the adjoining section of the gut, is a plain walled 

 tube lined with the usual vacuolated, granular digestive cells. More posteriorly 

 lateral pouches of irregular form appear (Plate 38, fig. 1) and may be found at 

 fairly regular intervals as far as the anterior end of the pericardium. Here the 

 canal rapidly narrows, becomes circular in outline (Plate 38, figs. 7, 9) the epithe- 

 lial lining is reduced in height and by a slender pore it opens into the cloacal 

 chamber whose form and relations are represented (Plate 38, fig. 2). It may be 

 added in this connection that the walls of the cloaca are devoid of folds, glandu- 

 lar appendages, or modifications of any definite character. 



The pericardial cavity is of moderate size but in one respect differs from that 

 of any other Solenogastre. Immediately behind the opening into the gonad 

 the pericardial wall forms two latero-ventral outpouchings of considerable 

 length (Plate 38, figs. 2, 7). The component cells are low columnar in form, 

 without definite signs of glandular activity and contain relatively large dense 

 nuclei. It is impossible to determine their function though they may be seminal 

 vesicles since cells of the same general appearance compose the lateral peri- 

 cardial wall and connect these diverticula with the inner openings of the coelo- 

 moducts. 



The heart is of average size and consists of two distinct divisions. The 

 anterior one, without any sharp boundary line is continuous with the aorta 

 which, throughout its entire length, is a tube of more than usually great size. 

 Its connections with the gonad and the anterior end of the bodj' are normal as 

 are those of the visceral sinus. Large blood spaces occur about the cloacal 

 cavity and as the walls of the latter are thin the exchange of gases may readily 

 take place at this point. The blood corpuscles vary considerably in shape, in 

 some cases being similar to the elongated type found in Strophomenia and at 

 other times appearing almost globular. This may be a post mortem effect but 

 the cells are very well preserved. 



