1941 CATALOGUE OF FISHES OF TORTUGAS 2 ^ 



and cranial bones as they lie on the meninges. Posterior to the brain the two pass 

 toward the median plane, where they run as a single line, rising slowly from 

 vertebral level toward end of base of second dorsal. A short median and two very 

 distinct lateral meningeal lines are present. The latter are mediad to the strong 

 postocular stripes of the superficial pattern. A dark line on the peritoneum con- 

 tinues beneath the vertebral column and into the caudal peduncle. Three vertical 

 bars of dark pigment in the trunk unite the median ventral and dorsal stripes. 



Surface and internal patterns register perfectly. Both are subject to change in 

 shade with the shade of the fish's surroundings. The surface pattern on trunk 

 and tail is often much fainter than the internal one." Both are highly effective in 

 assimilating the species to the sandy bottom it haunts. 



The eggs were collected on July 7 and 8, 1927. One deposit was beneath dead 

 coral on a sloping bank cutting off a small section from the upper deep hole 

 within Bird Key reef; the other similarly placed in one of the deeper holes in 

 the northern part of Loggerhead shoal. Clean white sand, freshly excavated and 

 scattered over a dark surface, betrayed the site of the first nest discovered, as did 

 the large goby slipping under cover as it was approached. Other similar nesting 

 places were seen later in preparation, with the fish carrying away sand in its 

 mouth and casting it aside. 



The egg mass of one nest looked like a smear of thick, rather translucent paste. 

 It was 50 mm. in diameter, and on the under side of a stone measuring 200 by 

 300 mm. Each egg was contained in a very delicate envelope measuring 0.95 by 

 0.42 mm., rounded distally, where the egg proper lies, and pointed at the attached 

 pole. The degree of difference in shape at the two ends varies from nest to nest, 

 in part with the stage of development. 



The guardian of the eggs in each of the observed instances was a male, readily 

 distinguished by its long urogenital papilla, sharply contrasting with the short 

 broad one of the female, as is usual among gobies. The instinct of one of these 

 fish to protect the eggs in his keeping is strong, as was shown by repeated attacks 

 on a marauding swarm of Halichoeres biuittatus. W. H. L. 



The collection contains 16 specimens, 22 to 53 mm. long. The raised mem- 

 branous fold on the median line of the nape, which has been considered of 

 generic importance by some recent authors, is present in all these specimens, in- 

 cluding the smallest one. 



West Indies to Florida. S. F. H. 



Microgobius Poey 



Microgobius Poey, Enumeratio, 1875, p. 126 (M. signatus Poey). 

 Xenogobius Metzelaar, Trop. atl. Vissch., 1919, p. 140 (X. weberi Metzelaar). 



In his description of Xenogobius weberi Metzelaar stated that the head is 

 naked, and it doubtless is so in spite of the fact that his artist has shown it rather 

 well covered with scales. Text and illustration together indicate clearly a species 

 of Microgobius, for the presence of a patch of ctenoid scales behind the pectoral 

 fin is no distinctive mark. It occurs in the species recently described, which is 



