MUSEUM OF COMPAKATIVE ZOOLOGY. 9 



naked. The color is darker or lighter violet or brown; the pedicels are yel- 

 lowish and the tentacles blackish. Probably the animal is dark in living state. 

 The calcareous ring is devoid of posterior prolongations, and in a low state of 

 development. The deposits consist of numerous thick, roundish, oval or elon- 

 gate, irregular perforated plates, which, contrary to the figure drawn by Semper, 

 often present uneven surfaces from the presence of low elevations or knobs. 

 However, the plates not unfrequently seem to be quite smooth. The number 

 of perforations is variable. The pedicels are supported by elongate simple or 

 three-armed perforated spicules or rod-like plates, and possess a very fragmen- 

 tary terminal plate. In one of the specimens the exterior layer of the perisome 

 contains small, scattered, irregularly formed perforated spicules, which are either 

 simple or irregularly three- or four-armed. These spicules, which are of much 

 finer construction than the underlying plates, are probably dissolved in the 

 remaining specimens. The specimen from Magdalena Bay appears to possess 

 anal teeth (?). 



Habitat. Mazatlan ; three specimens. Magdalena Bay ; one specimen. 



Cucumaria dubiosa, Semper (var. 1). 



The specimens agree in all respects with the type described by Semper, 

 except that no interradial pedicels are to be distinguished. Considering, how- 

 ever, the very striking similarity in every other respect, I can only refer 

 them to the species of Semper. There is no doubt that Cucumaria miniata 

 also bears the greatest resemblance to this species ; a revision of all such forms 

 which are characterized by possessing the same kind of deposits is highly 

 desirable. 



Habitat. Eden Harbor in the Strait of Magellan (Hassler Exp.) ; several 

 specimens. Mayne Harbor in the Strait of Magellan (Hassler Exp.) ; one 

 specimen. Lat. 37° 42' S., Lon. 56° 20' W. (Hassler Exp.) ; depth 44 fath- 

 oms ; two specimens. 



Echinocucumis typica, Sars. 



Figrare 3. 



Some of the specimens, especially those brought home from Barbados and 

 St. Kitts, are remarkable in having an almost completely spherical body with 

 a highly reduced bivium, so that the oral and anal apertures closely approach 

 each other. The specimens obtained at Barbados reach 15 mm. in diameter, 

 and their whole appearance reminds one most strikingly of an Ascidian ; the 

 trivium is enormously developed ; the mouth and anus are each situated in a 

 small conical prominence on the upper part of the sphere. Otherwise they 

 seem to resemble the Norwegian Echinocucumis typica in almost every detail. 

 However, in the West Indian forms the pedicels seem, as a rule, to be smaller 



