1879.] NATURAL SCIENCES OF PHILADELPHIA. 31 



DESCRIPTION OF A NEW SPECIES OF GONIOBRANCHUS. 

 BY ANDREW GARRETT. 



Goniobranchus albopunctatus, Garr. 



Animal elongate-oval, depressed, the two ends equally rounded, 

 a little the widest at the middle, and, when in motion, it becomes 

 more elongate, and the sides nearly parallel. The dorsal region 

 is depressl}' convex, smooth, and the margins of mantle thin. The 

 upper surface is bright orange-}'ellow, with crowded opaque white 

 dots, and minute annulas; the mantle with a band of small irregu- 

 lar lemon-yellow spots near the margin, which latter is edged with 

 violaceous. 



The dorsal tentacles, which issue from simple orifices, are elon- 

 gate ovate, sub-mucronate, somewhat trigonal, purple-brown, pro- 

 fusely dotted with opaque white, and marked with two vertical 

 lines of the latter color. 



The branchial plumes are rather large, twelve in number, con- 

 nate at their base, decreasing in size posteriori y, and encircling 

 the prominent anal tube; they are colored and dotted similar to 

 the tentacles, and each ornamented with two longitudinal white 

 lines. 



The under surface of the mantle and foot are pale lemon-yellow, 

 the former margined the same as above. 



The head is small, and furnished with moderate, obtuse, cylin- 

 drical tapering labial appendages. 



The foot is elongate, narrow, obtusely rounded in front, sides 

 parallel, rounded behind, and, when in motion, extends consider- 

 ably behind the mantle. 



Length, 62 ; diameter, 20 millimetres. 



Bab. Huahine, Society Islands. 



A very rare species found on weedy bottom in the upper region 

 of the laminarian zone, and is the only example which has occur- 

 red to my notice during ten years collecting in the group. 



