124 STROPHOMENIA SPINOSA. 



and radial fibres attaching to the body wall. As may be seen in Plate 8, fig. 2, 

 numerous pyriform masses of cells attach to the pharynx throughout its entire 

 extent and pour the secretion into the digestive canal through numerous inter- 

 cellular openings. The ventral salivary glands are long tubular bodies with a 

 very slender duct through which the attached gland cells pour their secretion. 

 Their openings into the pharynx are exceedingly narrow but occur in normal 

 position at the sides of the radula (Plate 17, fig. 4). The long dorsal coecum, 

 the fairly regularly pouched mid gut, and the relations of the rectum arc all 

 typical. 



The radula is evidently in a highly degenerate condition, and differs con- 

 siderably in different specimens. In the individual represented (Plate 34, fig. 8), 

 it is exceedingly minute and appears to be clearly monoserial. In Plate 34, 

 figs. 8, 9, it is considerably larger, biserial and the teeth next the median line 

 are noticeably smaller than the others. Judging from the specimen possessing 

 the larger radula (Plate 34, fig. 10), there are eight transverse rows. 



The heart is the usual long, tubular organ represented in cross section 

 (Plate 17, fig. 5) and the other features of the circulatory system arc so typical 

 of the genus that they require no further comment. The corpuscles ai'c very 

 similar in outline to the spines of Limifossor taJpoidcus, being pointed ovate in 

 shape. The nucleus is superficially placed, and may protrude somewhat beyond 

 the general level of the cell. 



The gonad in its position and the development of the sex products is normal ; 

 and its connection with the pericardium is made, as usual with this genus, by 

 means of canals of unusually large calibre (Plate 9, fig. 4). Posteriorly the 

 pericardial wall is produced into two pouches, separated by the sinus entering 

 the heart, which are continuous with the coelomoducts. The lateral surfaces 

 of these pouches and the pericardial wall for some distance in front of them, and 

 especially the coelomoducts themselves as far as the seminal receptacles, are 

 ciliated, the coat being especially heavy in these last named tubes. Roughly 

 the height of the cells of these regions is proportional to the thickness of the 

 ciliated coat, ranging from flat or cubical elements in the pericardium to those 

 in the neighborhood of the seminal receptacles where the ratio of height to 

 thickness is about 3:1., The larger cells are developed into a few longitudinal 

 folds and are endowed with a considerable degree of glandular activity. 



The ventral section of the coelomoduct, or shell gland, is joined somewhat 

 behind its anterior end by the dorsal section, and the blind sac thus developed 

 serves for the attachment of a greater number of seminal receptacles than in any 



