OPISTHOBBANCHIATE MOLLUSCA FROM MONTEREY BAY. 123 



Rhachis liroad, naked. Pleural teeth similar in shape, strongly falcate, compressed, the inner 2 

 or 3 (pi. .xviii, fig. 22) smaller than those following, the outermost ones also strongly reduced in size 

 (pi. XVIII, fig. 23). Upon the inner side of each tooth a narrow wing-like expansion which is con- 

 tinued as a decreasing thickening up alone the back of the tooth toward the tip (pi. xviii, fig. 24). 



Habitat: In rocky tide pools of the fucoid zone all along the southern coast of Monterey Bay. 

 Not abundant but lia.s been taken at all times of the year. The species has a wide range, having been 

 recorded from Sitka, Unalaska, Puget Sound, Monterey Bay, Santa Barbara, and San Diego, and in a 

 light colored variety, D. sandiegenxis, var. pallida Bergh NNE. of Punta Delgada, off the coast of 

 Patagonia in S. lat. 42° 24', W. long. 61° .38'. 



At Monterey the breeding season occurs principally during the summer months, but individuals 

 have dejiosited their eggs in the aijuaria at the Hopkins laboratory in December and January, and the 

 hroail white spiral egg bands of this species have been found in the tide pools at thesame time, though 

 not as abundantly as during the months of June, July, and August. 



This species was discovered and superficially described by Cooper (1862) and afterwards more 

 (nll\' liy P>er£rh I isso), whose careful account of the anatomy of the form, baseil upon specimens from 

 .Alaska, is amply snliicient for its ready recognition. 



A si)tTinK'n deposited in U. S. National Museum (no. 181288). 



Genus 6. ALDISA Bergh. 



Aldisa Bergh. Malacol. Unters., H. XIV. ls7S. p. XXXVIII. Gattiingen niirdischer Doriden. Arch. f. Naturgeseh.. 

 XLV, 1. 1879. p. 348. System der Nudibr. Gasteropoden, 1892, p. 106. Nudibranche.s et Marsenia provenant des 

 Campagne.s de la Princesse- Alice (1891-1897), R^s. Camp. Scl. Albert I" de Monaco, Fasc. XIV, 1899, p. 7. 

 Tentacles tubercule-like or auriform. Pleural teeth erect, rod-like, the external margin serrulate, 

 (ilans penis armed. 



6. Aldisa sanguinea (Cooper)." 

 [I'l. XXIV, tig. 7. pi. XVIII, tigs. 2.5-2U: pi. xxi, figs. 112, 114.] 



Doris {Asteronotm) mnguinea Cooper, Proc. Cal. Acad. Nat. Sci., II, 1862, p. 204; III, 1863. p. .58. 

 Asteronoiusf sangiiineus Bergh, System der Nudibr. Gasteropoden, 1892, p. 111. 

 Atclisa sauguinea MacFarland, op. cit., p. 42. 



Body somewhat depressed, oval, the ends about equally rounded. Dorsum everywhere thickly 

 covered with small conical tubercules, the general color light to dark red (PI. .x.xiv, fig. 7), sprinkled 

 everywhere with very minute black spots. On the median line immediately in front of the branchiae a 

 large rounded or oval spot of black, another similar spot in median line just behind the rhinophores, 

 which often is very much elongated or divided into 2, one l)ehind the other. The.se spots may vary 

 in size and number, but seem to be quite constant in color marking. In alcoholic specimens the black 

 spots become greenish, the red color disappearing entirely. 



Margin of mantle rather thick, covering the foot everywhere, except at the extreme tip of the 

 tail, when the animal is crawling. 



The foot is abruptly rounded in front, less so behind, the sides slightly converging posteriorly. 

 .\nterior margin of foot bilabiate, the upper lip thin, undivided. Color everywhere beneath light to 

 dark red. 



Total length up to 17 mm. with a width of 8 mm. and a height of 6 mm. Lent;th of foot nf same 

 specimen, 13 mm; its greatest width, 6 mm. 



Head small, concealed between mantle and foot ; the tentacles short, auriform, witli a clearly marked 

 external longitudinal groove. 



Khinophoies rather stout, the .stalk cylindro-conical, the clavus dilated, conical, tapering to a 

 blunt til), perfoliate with about 12-15 leaves, the whole organ deeply retractile into a sheath, the low 

 margin of which bears scattered, rounded tubercules, similar to those of the dorsum. 



Branchial plumes, 8-10, simply pinnate or irregularly bipinnate, arranged in a circle, i-ompletely 

 retractile into a sheath, with low tuberculate margin. Anal papilla low, centrally placed. 



Blood gland very thin and small, the anterior lobe almost rudimentary, the posterior lobe lying 

 transversely tipon and behind the central nervous system. 



"Cooper's very fragmentary description is as follows: "Brilliant red, with 

 distributed. Surface .smooth: dorsal tentacles short; branchiae composed of 8 .simply 

 posterior end of the body. Length, 5 inch; breadth, i inch: height, about the same.' 



