100 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 8 



Spicules an external layer of regular baskets, the hollow part formed 

 by broad bars, the narrow rim with few teeth. An inner layer of regular 

 4-holed knobbed buttons and larger knobbed plates and huge reticulated 

 grains. Ventral feet mostly with a minute end plate and the walls packed 

 with supporting rods mostly 3-armed, smooth to knobbed. Dorsal ap- 

 pendages apparently lacking end plate but with heavier 3-armed rods. 

 Introvert with a few oblong buttons smooth or knobbed. Tentacles with 

 stems packed with narrow plates or rods, smaller, curved and often 3- 

 armed rods in the finer branches. 



Type. — Possibly in Germany. 



Type locality. — Peru, probably at comparatively low depth. 



Distribution. — From Peru to Mexico. 



Depth. — The Hancock material came from 25 fms. 



Specimens examined. — The following specimens from the Allan Han- 

 cock Expeditions: 



264-34. Petatlan Bay, Mexico, 25 fms., south and west of White 

 Friars Island, rock with gorgonids, 4 specimens. 



Remarks. — The 4 specimens measure between 3-4 cm. in length and 

 are thus somewhat larger than the types which measured only 15-18 mm. 

 Semper's description is not veiy detailed,^ and his figure of a basket 

 shows a more irregular type than the one which commonly occurs. He 

 mentions hollow knobbed bodies and large smooth plates, the latter re- 

 ferring possibly to the smooth supporting plates. He gives, however, no 

 reference to the regular 4-holed knobbed buttons, possibly because he 

 considers them growth stages of the larger knobbed bodies; also they 

 may possibly be more scarce in younger individuals. It must further be 

 mentioned that the ventral tentacles in the present material are very 

 slightly smaller in size than the other. 



5 Semper's original description: "Zehn Tentaklen, die zwei ventralen kleine. 

 Habitus Ascidien-artig. Auf den Riicken stehen die Ambulacral-papillen regellos 

 zerstreut, am Bauche in drei deutlichen Reihen, deren jede zwei Fiisschen in der 

 Breite zeigt. Es bleibt sich eine Art Bauchscheibe dadurch das die Fiisschen 

 hinten in Ambulacral-papillen iibergehen. Farbe gelblich (im Spiritus). Drei 

 Exsemplare, 15-18 mm. lang, 6-7 mm. breit. 



Am Gefassring eine einzige Polische Blase, eine kleine dorsaler Steinkanal. 

 Lungen fast so lang wie der Korper, mit wenig, aber sehr langen einfachen 

 Nebenasten. Geschlechtsteile zwei Biischel sehr kleiner unveriistelter Schlauche, 

 ihre Basis am Mesenterium sehr weit nach vorne, vor dem Wassergefassring. 

 Kalkring aus 10 einfachen Gliedern bestechend; die Radialen et^vas breiter als 

 die Interradialen, nicht nach hinten verlanget. Keine Kaumagen. Die Retraktoren 

 inserieren sich in der Mitte des Korpers. 



Grosse glatte Kalkplatten in der ganz starre Haut, dariiber ein Schicht 

 durchbrochenene, etwas knotiger Halbkugeln." 



