TETHYS-AUSTRALASIAN. 97 



Mantle dirty white, with slight gray clouds, its free right margin 

 (inflexed and not shown in figure) olive with bold confluent maculse 

 of black. Inner surface of swimming lobes olivaceous, boldly marked 

 with confluent black maculae, the lighter tint prevailing toward edges 

 of the lobes. Sole uniform olivaceous. 



Shell moderately convex, ovate, yellow outside, becoming brown- 

 ish toward the margins, the epidermal layer projecting well beyond 

 the moderately solid, white, calcareous layer. Beak well incurved, 

 enveloped by a very ample callous, reflexed "hood" which is not 

 adnate dorsally but leaves a large, deep, triangular cavity (fig. 24). 

 Sinus rather short and moderately concave, its inflexed cuticular mar- 

 gin conspicuous and nodular above. Surface with inconspicuous 

 growth striae and many shallow radial grooves. Length 54, breadth 

 45 mill. 



Upolu, Samoa Is. (Dr. Graffe). 



Aplysia sp.f Museum Godeffroy, Catalog IV, p. 105, No. 1107a. 

 Hamburg, 189. 



This form, which I name in honor of the founder of the Manual, 

 is allied to T. keraudrenii in size, coloration and ample proportions 

 of the swimming lobes. It differs from that in the star-like pore of 

 the mantle, in place of a conspicuous tube, and in the greater devel- 

 opment of the reflexed callus at the shell's apex. The posterior 

 sinus of the shell, too, is shorter ; and the excurrent siphon of mantle 

 is rather less developed, although of the same essential structure. T. 

 pulmonica Gld. is also a species of similar characters, but it appar- 

 ently has a more extensive posterior union of the swimming lobes, 

 producing the sack-like structure described by Gould, and it lacks 

 black maculation. 



V. Species of New Zealand and Australian Seas. 



These forms are still too imperfectly known to admit of tabula- 

 tion in the form of a " key." 



T. BRUNNEA Huttou. PI. 59, fig. 44. 



Animal of a uniform rich dark brown, about 4 inches in length. 

 Shell horny, ear-shaped, firm, the whole shell very finely concen- 

 trically striated ; epidermis pale brown. Length '9, breadth *7 

 inch. The shell somewhat resembles A. exeavata Sow., from Port 

 Jackson, but it is not square at the end. (Button.) 



Wellington and Dunedin, New Zealand. 

 7 



