Ol'ISTHOBRANCHlATE MOLLUSCA F-ROM MONTEREY BAY. 137 



thence in a broad loop backward to the anus. Total length of the intestine about 23 mm. The liver 

 is bluntly conical behind, its surface smooth, the anterior end bluntly flattened. The oblique groove 

 in which tlie stimiach is included divides it alnidj^f coiupU'tely into two unequal lobes. 



Tlif lierniajihroditic gland covers nearly I In- whi.lf si ii face of the liver with its rather thick lobules. 

 The heriuaphroditic duct is very long and sli-ndei, and, arising from the anterior dorsal side of the 

 groove in the liver, courses forward and downward to the posterior face of the anterior genital 

 mass, where it describes a series of irregular loop.s between the spermatotheca on the left and the 

 nidamental and albumin glands on the right, this portion being slightly more dilated than the first 

 part of the hermaphroditic duct, thus forming the hermaphroditic ampulla. At the anterior end of the 

 nidamental gland the ampulla constricts again, gives off the spermatic duct, and passes into the 

 nidamental gland. The spermatic duct dilates almost at once into the long, thick, lobulated prostate 

 gland, about 14 mm. in length by 2 mm. in breadth, which describes a loop (pi. xxi, fig. 113, pr.) upon 

 the anterior face of the anterior genital mass, the distal end of the loop being again bent upward upon 

 itself. A convoluted vas deferens succeeds the prostate for about 4.5 mm., dilating at the upper 

 anterior surface of the anterior genital mass into the obliquely placed cylindrical ampulla, 4.5 mm. 

 long by 2 mm. in diameter, its distal end directed toward the median line of the animal and doubling 

 sharply outward toward the penis, into which it dilates. Glans penis and distal portion of lining of 

 its lumen armed with minute hooks. 



The vagina, 4 mm. in length by 1 mm. in extreme diameter, passes straight inward into the short 

 vaginal duct, which opens through the outer anterior wall of the large spherical spermatotheca. The 

 latter organ (pi. xxi, fig. 113, sp. th. ) is about 5 mm. in diameter and makes up about one-half the bulk 

 of the anterior of the genital mass. From its anterior face is given off the uterine duct close to 

 the entrance of the vaginal duct. After a short course this duct passes, as usual, into the nidamental 

 gland at its anterior inner face, receiving midway of its length the very short and slender duct of 

 the spermatocyst. The spermatocyst (fig. 113, sp.c.) is pear-shaped, 2 mm. long by 0.7 mm. in greatest 

 diameter, and is placed transversely upon the upper anterior portion of the nidamental gland in 

 contact with and partly covered by the proximal end of the prostate gland. 



Dimensions of largest preserved specimen, scarcely at all shrunken: Length, 60 mm.; height, 

 immediately in front of branchite, 29 mm. ; greatest width, 15 mm. ; width of head, 15 mm. ; maximum 

 height of dorso-lateral processes, 3 mm.; length of foot, 57 mm.; its greatest breadth, 7 mm. 



Habitat: On brown kelp of thefucoid zone and under overhanging rocks in tide pools everywhere 

 along the rocky coast from Monterey to Point Lobos. Altogether the most common nudibraiuh of the 

 region and the most conspicuous one, owing to the contrast of the bright orange color of its appendages 

 with the white of the body. It is avoided by the tide-pool fishes as apparently inedible, its bright 

 colors seemingly serving a warning purpose. 



A specimen deposited in U. S. National Museum (no. 181291). 



The fragmentary description of Stearns (1873)3 jg liased entirely upon external features, but is 

 sufficient to render t'Citain the identification of living specimens. The foregoing l)rief anatomical 

 description, especially the stnu-ture of the radula, shows that this is a species distinct from Triojilia 

 modesta Bergh, with which it Ijas lieeu united liy the latter writer (Bergh, 1894, 1. c. ). 



14. Triopha maculata MacFarland. 



[PI. XXVIII, fiK !>-: I'l- XIX. fiK^. S.M-oSI: Jil. XXI, tigs. 1011, 107.] 

 Trioplm iiiaeulaia JlacFnrland, op. cit., p. 49. 



Body limaciform, strongly rounded above, plump, the back passing over insensibly into the sides 

 save for the line of processes which indicate the boundary. Sides slightly compressed, a shallow longi- 

 tudinal groove immediately above the margin of the foot. Foot linear, bluntly rounded in front, 

 less so behind. Head flattened in front, sloping forward from the rhinophores to the wide semicir- 

 cular frontal margin, which bears a fringe of from 10 to 12 short, stout processes, each of which toward 



« "Animal shig-shaped: anteriorly obtusely rounded, posteriorly pointed, somewhat attenuated; cephalic tentacles 

 clavate, upper part of same of an orange color, below white; gill plumes 5, arborescent, resembling fern leaves, tipped 

 with orange; plumes and tentacles ,"5 inch in length; the former situated in the middle of the bacli somewhat posterior 

 to the center. Six tentacular processes on each side, tipped with orange and ,\ inch long: also short tentacular processes 

 in front of the head: body I5 inches in length, translticent white, covered with fine papillae of an orange color. Habitat: 

 Monterey, at Point Pinos, near the light-house, on the under side of granite rocks at edge of laminarian zone." 



