Ig4 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxv. 



that species from La Jolla serving for comparison. It was also noted 

 that they did not differ in any structural detail from R. muscarum, 

 the type of which was available for study. It was apparent, there- 

 fore, that the two species were identical, but to make the matter cer- 

 tain, the writer sent two of Doctor Heath's specimens to the U. S. 

 National Museum, at the same time asking Mr. B. A. Bean to 

 compare them with the type of R. eigenmanni. This Mr. Bean 

 kindly did, with the following observations: 



Mr. McKnew and I have examined the specimens of Rimicola in this Museum 

 and find that the type of A*, eigenmanni has but four rays in the dorsal fin ; in 

 the only additional specimen of A'. eigenmanni preserved here there are five 

 rays in the dorsal. This fish, which is about the size of the type, was taken in 

 1898 off Point Loma, California. The cotype of R. muscarum seems to have 

 but five rays in the dorsal fin; the count, however, is uncertain, owing to the 

 mutilated condition of the fin. One of the specimens recently received from 

 you has six rays, but the smaller one of the two has five. We think with you 

 that A', muscarum and A', eigenmanni are identical, the smaller specimens hav- 

 ing fewer developed rays in the dorsal. Otherwise the specimens look alike 

 to us. 



In reading the original descriptions of R. eigenmanni and R. 

 m used i um it will be noted that the species differ in color, in the num- 

 ber of dorsal rays, and perhaps in minor details. The color of R. 

 in us, um in was described and figured from an alcoholic specimen, 

 and differs from that of R. eigenmanni (which is said to be uniform 

 light olive green) in having a yellowish body with small, reddish 

 spots and a lateral stripe of the same color. That the color pattern 

 is variable is shown by the cotype of R. muscarum, which has spots 

 on the head only, while the lateral stripe is imperfectly developed. 

 The light body color has been accounted for. A parallel case of 

 color change is found in two species of Aspasma, a related genus 

 from Japan, where specimens change from brownish to pinkish yel- 

 low in the preservative, while in some individuals pinkish spots and 

 a lateral stripe appear, Regarding the dorsal rays, of which R. 

 < igenmanni is said to have 4 and R. muscarum 6, a reference to the 

 appended table will show that among 8 specimens from Pacific Grove 

 they vary from 4 to 5. In each case the first dorsal ray has been 

 regarded as single, when if closely examined it will be found to con- 

 sist of a slender, spine-like ray closely attached to a larger, branched 

 one. The rays in the type of R. muscarum have been thus separated 

 ami collided as 6. The body grows more robust and heavy with age, 

 the smaller individuals being comparatively slender. The length of 

 the head, diameter of eye, height of fins, and other characters vary 

 somewhat as shown by the table of measurements. The anterior nos- 

 tril has a tube the posterior edge of which is prolonged, forming a 

 tentacle equal in height to half the diameter of eye. There is a con- 

 spicuous anal papilla. 



